Index: RController.m
===================================================================
--- RController.m	(revision 612)
+++ RController.m	(working copy)
@@ -888,7 +888,14 @@
 	
 /* Allow changes only for uncommitted text */
 - (BOOL)textView:(NSTextView *)textView shouldChangeTextInRange:(NSRange)affectedCharRange replacementString:(NSString *)replacementString {
-    return affectedCharRange.location >= committedLength;
+	if(affectedCharRange.location < committedLength) {
+		NSRange endOfEntry = NSMakeRange([[[textView textStorage] string] length],0);
+		[[textView textStorage] replaceCharactersInRange:endOfEntry withString:replacementString];
+		endOfEntry.location += [replacementString length];
+		[textView setSelectedRange:endOfEntry];
+		return NO;
+	} else 
+		return YES;
 }
 	
 - (void) handleBusy: (BOOL) isBusy {