I don't know if this has been posted yet, I apologize if it has. I also apologize if it's in the wrong forum. One of the potential causes of this error happens to be temporal anti-alias. If TAA is enabled, obviously ATI Tool detects the swapping samples as artifacts. Hence when it says "subsequent images are not identical," it's being honest: they really aren't (since the samples are swapped every frame). This also causes issues when doing "scan for artifacts," as it detects artificial artifacts. I regged just to post this as I noticed some people were still having issues over at OCFaq and the bug submission area.