We captured a clip in HD 1080 24p uncompressed with burn-in timecode on the clip. In FCP 5.1 and 5.1.1, when we edit the clip into the timeline and enable the timecode overlay, it matches to the burn-in timecode.
However in FCP 5.1.2, the burn-in timecode does not match to the timecode overlay. It is 4 frames later so if the timecode on a particular frame is supposed to be 00:01:00:00, the clip's burn-in timecode shows up as 00:01:00:04. If I go to the beginning of the clip, the burn-in timecode is 4 frames later so somehow the clip has been slipped later by 4 frames and if I try to use the Slip Tool to slip the clip, I can see the actual timecode that it is suppose to show by it doesn't allow me to slip anything. This is definitely a bug in FCP 5.1.2 as it did not show up in FCP 5.1 or 5.1.1 and I went back and forth between versions to confirm this.
What is interesting is that if you do any kind of render, the rendered portion of the clip will then slip back to the correct frame position so that the burn-in timecode now matches the timecode overlay.
If anyone can try this, capture a HD 1080 24p clip with burn-in timecode and edit it into a timeline in FCP 5.1.2 and compare the burn-in timecode with the timecode overlay and confirm if you get the same result.
This does not affect HD 1080 50i clip which I tested.