What version are you running?
1.5.5
What's the URL of the page containing the problem?
internal
What steps will reproduce the problem?
there is no exact procedure to re-produce it at the moment, needs more work to find out under which condition it produces incorrect diff results.
What is the expected output? What do you see instead?
instead of showing added/removed lines (green/red) it shows some lines as changed only (plain yellow). attached is the screen shot of the incorrect diff displaying.
What operating system are you using? What browser?
ubuntu 10.04, FireFox, Chrome
Please provide any additional information below.