diff --git a/GLFileView.m b/GLFileView.m
index f1d5fbc..579bee9 100644
--- a/GLFileView.m
+++ b/GLFileView.m
@@ -73,10 +73,6 @@
 					   @"h", ITEM_IDENTIFIER, 
 					   @"HEAD", ITEM_NAME, 
 					   nil], 
-					  [NSDictionary dictionaryWithObjectsAndKeys:
-					   @"p", ITEM_IDENTIFIER, 
-					   @"Previous", ITEM_NAME, 
-					   nil], 
 					  nil];
 	[self.groups addObject:[NSDictionary dictionaryWithObjectsAndKeys:
 							[NSNumber numberWithBool:NO], GROUP_SEPARATOR, 
@@ -93,29 +89,34 @@
 
 - (void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
 {
-	//NSLog(@"keyPath=%@ change=%@ context=%@ object=%@ \n %@",keyPath,change,context,object,[historyController.treeController selectedObjects]);
 	[self showFile];
 }
 
 - (void) showFile
 {
+	NSError *theError = nil;
 	NSArray *files=[historyController.treeController selectedObjects];
 	if ([files count]>0) {
 		PBGitTree *file=[files objectAtIndex:0];
-		
+
 		NSString *fileTxt = @"";
-		if(startFile==@"fileview")
-			fileTxt=[self parseHTML:[file textContents]];
-		else if(startFile==@"blame")
-			fileTxt=[self parseBlame:[file blame]];
-		else if(startFile==@"log")
-			fileTxt=[file log:logFormat];		
-		else if(startFile==@"diff")
-			fileTxt=[file diff:diffType];
+		if(startFile==@"fileview"){
+			fileTxt=[self parseHTML:[file textContents:&theError]];
+		}else if(startFile==@"blame"){
+			fileTxt=[self parseBlame:[file blame:&theError]];
+		}else if(startFile==@"log"){
+			fileTxt=[file log:logFormat error:&theError];		
+		}else if(startFile==@"diff"){
+			fileTxt=[file diff:diffType error:&theError];
+		}
 		
 		id script = [view windowScriptObject];
-		NSString *filePath = [file fullPath];
-		[script callWebScriptMethod:@"showFile" withArguments:[NSArray arrayWithObjects:fileTxt, filePath, nil]];
+		if(theError==nil){
+			NSString *filePath = [file fullPath];
+			[script callWebScriptMethod:@"showFile" withArguments:[NSArray arrayWithObjects:fileTxt, filePath, nil]];
+		}else{
+			[script callWebScriptMethod:@"setMessage" withArguments:[NSArray arrayWithObjects:[theError localizedDescription], nil]];
+		}
 	}
 	
 #if 0
@@ -174,7 +175,8 @@
 
 - (void)scopeBar:(MGScopeBar *)theScopeBar selectedStateChanged:(BOOL)selected forItem:(NSString *)identifier inGroup:(int)groupNumber
 {
-	if(groupNumber==0){
+	NSLog(@"startFile=%@ identifier=%@ groupNumber=%d",startFile,identifier,groupNumber);
+	if((groupNumber==0) && (startFile!=identifier)){
 		NSString *path = [NSString stringWithFormat:@"html/views/%@", identifier];
 		NSString *html = [[NSBundle mainBundle] pathForResource:@"index" ofType:@"html" inDirectory:path];
 		NSURLRequest * request = [NSURLRequest requestWithURL:[NSURL fileURLWithPath:html]];
diff --git a/PBGitHistoryController.m b/PBGitHistoryController.m
index 03e5c9e..c4037c2 100644
--- a/PBGitHistoryController.m
+++ b/PBGitHistoryController.m
@@ -228,46 +228,31 @@
 {
     if ([(NSString *)context isEqualToString: @"commitChange"]) {
 		[self updateKeys];
-		[self restoreFileBrowserSelection];
-		return;
-	}
-
-	if ([(NSString *)context isEqualToString: @"treeChange"]) {
+		//[self restoreFileBrowserSelection];
+	}else if ([(NSString *)context isEqualToString: @"treeChange"]) {
 		[self updateQuicklookForce: NO];
 		[self saveFileBrowserSelection];
-		return;
-	}
-
-	if([(NSString *)context isEqualToString:@"branchChange"]) {
+	}else if([(NSString *)context isEqualToString:@"branchChange"]) {
 		// Reset the sorting
 		if ([[commitController sortDescriptors] count])
 			[commitController setSortDescriptors:[NSArray array]];
 		[self updateBranchFilterMatrix];
-		return;
-	}
-
-	if([(NSString *)context isEqualToString:@"updateRefs"]) {
+	}else if([(NSString *)context isEqualToString:@"updateRefs"]) {
 		[commitController rearrangeObjects];
-		return;
-	}
-
-	if ([(NSString *)context isEqualToString:@"branchFilterChange"]) {
+	}else if ([(NSString *)context isEqualToString:@"branchFilterChange"]) {
 		[PBGitDefaults setBranchFilter:repository.currentBranchFilter];
 		[self updateBranchFilterMatrix];
-		return;
-	}
-
-	if([(NSString *)context isEqualToString:@"updateCommitCount"] || [(NSString *)context isEqualToString:@"revisionListUpdating"]) {
+	}else if([(NSString *)context isEqualToString:@"updateCommitCount"] || [(NSString *)context isEqualToString:@"revisionListUpdating"]) {
 		[self updateStatus];
 
 		if ([repository.currentBranch isSimpleRef])
 			[self selectCommit:[repository shaForRef:[repository.currentBranch ref]]];
 		else
 			[self selectCommit:[[self firstCommit] sha]];
-		return;
+	}else{
+		[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
 	}
 
-	[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
 }
 
 - (IBAction) openSelectedFile:(id)sender
diff --git a/PBGitTree.h b/PBGitTree.h
index 7b948d3..27cef62 100644
--- a/PBGitTree.h
+++ b/PBGitTree.h
@@ -26,10 +26,11 @@
 + (PBGitTree*) rootForCommit: (id) commit;
 + (PBGitTree*) treeForTree: (PBGitTree*) tree andPath: (NSString*) path;
 - (void) saveToFolder: (NSString *) directory;
-- (NSString *)textContents;
-- (NSString *)blame;
-- (NSString *) log:(NSString *)format;
-- (NSString *) diff:(NSString *)format;
+
+- (NSString *) textContents:(NSError **)anError;
+- (NSString *) blame:(NSError **)anError;
+- (NSString *) log:(NSString *)format error:(NSError **)anError;
+- (NSString *) diff:(NSString *)format error:(NSError **)anError;
 
 - (NSString*) tmpFileNameForContents;
 - (long long)fileSize;
diff --git a/PBGitTree.m b/PBGitTree.m
index 7a011b3..2f7af52 100644
--- a/PBGitTree.m
+++ b/PBGitTree.m
@@ -115,73 +115,100 @@
 	return [repository outputForArguments:[NSArray arrayWithObjects:@"show", [self refSpec], nil]];
 }
 
-- (NSString *) blame
+- (NSString *) blame:(NSError **)anError
 {
+	NSString *error=nil;
+	NSString *res=nil;
 	if (!leaf)
-		return [NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
+		error=[NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
 	
 	if ([self hasBinaryAttributes])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
+		error=[NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
 	
 	if ([self fileSize] > 52428800) // ~50MB
-		return [NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
+		error=[NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
 	
-	NSString *contents=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"blame", @"-p",  sha, @"--", [self fullPath], nil]];
-	
-	if ([self hasBinaryHeader:contents])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-	
-	
-	return contents;
-}
-
-- (NSString *) log:(NSString *)format
-{
-	if (!leaf)
-		return [NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
-	
-	if ([self hasBinaryAttributes])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-	
-	if ([self fileSize] > 52428800) // ~50MB
-		return [NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
-	
-	NSString *contents=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"log", [NSString stringWithFormat:@"--pretty=format:%@",format], @"--", [self fullPath], nil]];
-	
-	if ([self hasBinaryHeader:contents])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-	
-	
-	return contents;
-}
-
-- (NSString *) diff:(NSString *)format
-{
-	if (!leaf)
-		return [NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
-	
-	if ([self hasBinaryAttributes])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-	
-	if ([self fileSize] > 52428800) // ~50MB
-		return [NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
-	
-	NSString *contents=@"";
-	if(format==@"p") {
-		contents=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", sha, [NSString stringWithFormat:@"%@^",sha],[self fullPath], nil]];
-	}else if(format==@"h") {
-		contents=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", sha, @"HEAD",[self fullPath], nil]];
-	}else if(format==@"l") {
-		contents=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", sha, @"--",[self fullPath], nil]];
+	if(error==nil){
+		res=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"blame", @"-p",  sha, @"--", [self fullPath], nil]];
+	}else{
+		*anError = [NSError errorWithDomain:@"blame" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error,NSLocalizedDescriptionKey,nil]];
 	}
-			   
-			   
 	
-	if ([self hasBinaryHeader:contents])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
+	return res;
+}
+
+- (NSString *) log:(NSString *)format error:(NSError **)anError
+{
+	NSString *error=nil;
+	NSString *res=nil;
+	if (!leaf)
+		error=[NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
 	
+	if(error==nil){
+		res=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"log", [NSString stringWithFormat:@"--pretty=format:%@",format], @"--", [self fullPath], nil]];
+	}else{
+		*anError = [NSError errorWithDomain:@"log" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error,NSLocalizedDescriptionKey,nil]];
+	}
 	
-	return contents;
+	return res;
+}
+
+- (NSString *) diff:(NSString *)format error:(NSError **)anError
+{
+	NSString *error=nil;
+	NSString *res=nil;
+	if (!leaf)
+		error=[NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
+	
+	if ([self hasBinaryAttributes])
+		error=[NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
+	
+	if ([self fileSize] > 52428800) // ~50MB
+		error=[NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
+	
+	if(error==nil){
+		NSString *des=@"";
+		if(format==@"p") {
+			des=[NSString stringWithFormat:@"%@^",sha];
+		}else if(format==@"h") {
+			des=@"HEAD";
+		}else{
+			des=@"--";
+		}
+		res=[repository outputInWorkdirForArguments:[NSArray arrayWithObjects:@"diff", sha, des,[self fullPath], nil]];
+		if ([res length]==0) {
+			NSLog(@"--%d",[res length]);
+			*anError = [NSError errorWithDomain:@"diff" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:@"No Diff",NSLocalizedDescriptionKey,nil]];
+		}else{
+			NSLog(@"--%@",[res substringToIndex:80]);
+		}
+	}else{
+		*anError = [NSError errorWithDomain:@"diff" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error,NSLocalizedDescriptionKey,nil]];
+	}
+
+	return res;
+}
+
+- (NSString *)textContents:(NSError **)anError
+{
+	NSString *error=nil;
+	NSString *res=nil;
+	if (!leaf)
+		error=[NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
+	
+	if ([self hasBinaryAttributes])
+		error=[NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
+	
+	if ([self fileSize] > 52428800) // ~50MB
+		error=[NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
+	
+	if(error==nil){
+		res = [self contents];
+	}else{
+		*anError = [NSError errorWithDomain:@"show" code:1 userInfo:[NSDictionary dictionaryWithObjectsAndKeys:error,NSLocalizedDescriptionKey,nil]];
+	}
+
+	return res;
 }
 
 - (long long)fileSize
@@ -200,25 +227,6 @@
 	return _fileSize;
 }
 
-- (NSString *)textContents
-{
-	if (!leaf)
-		return [NSString stringWithFormat:@"This is a tree with path %@", [self fullPath]];
-
-	if ([self hasBinaryAttributes])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-
-	if ([self fileSize] > 52428800) // ~50MB
-		return [NSString stringWithFormat:@"%@ is too big to be displayed (%d bytes)", [self fullPath], [self fileSize]];
-
-	NSString* contents = [self contents];
-
-	if ([self hasBinaryHeader:contents])
-		return [NSString stringWithFormat:@"%@ appears to be a binary file of %d bytes", [self fullPath], [self fileSize]];
-
-	return contents;
-}
-
 - (void) saveToFolder: (NSString *) dir
 {
 	NSString* newName = [dir stringByAppendingPathComponent:path];
diff --git a/html/views/diff/diffWindow.js b/html/views/diff/diffWindow.js
index 8d60fc9..cee1133 100644
--- a/html/views/diff/diffWindow.js
+++ b/html/views/diff/diffWindow.js
@@ -6,7 +6,13 @@ var setMessage = function(message) {
 	$("diff").style.display = "none";
 }
 
+var hideMessage = function() {
+	$("message").style.display = "none";
+	$("diff").style.display = "";
+}
+
 var showDiff = function(diff) {
+	hideMessage();
 	highlightDiff(diff, $("diff"));
 }