I’ve been dealing with the same problem on two features. Both also were Red shows using ProRes 422 transcoded offline clips merged with production audio. One was on 7.0.1 the other on 7.0.2 which I’m currently working on and still having the issue from time to time.
However, it’s also worth noting that it seems FCP has general trouble with the trim tool and merged clips.
In addition to the crashes that coincide with autosave where the color wheel appears before the program closes, at times certain edits when trimmed at all will cause the program to instantly crash. This will occur over and over again until I remove the clip from the timeline and replace it – after which it trims fine.
Of course this is not a solution as there is no way to predict when it will be a problem. I’ve tried to isolate it by changing playback settings, not cutting with audio crossfades, etc. Nothing I’ve tried seems to work.
Also, there is a bug in the trim window displays. When using merged clips that are by default linked, if sequence linking is turned off they display incorrect preview frames that are equal to the amount of black space at the head and tail of each merged clip where the audio runs longer than the picture.
This is also a problem when attempting to trim the video only by turning sequence linking off or by locking out the audio tracks once in the trim tool.
The only solution I’ve found is to manually unlink the audio and video and turn sequence linking off. Then it previews correctly.
This of course is a huge inconvenience as in feature editorial merged clips are the norm and the time involved in working around the trim preview becomes horribly time consuming, not to mention aggravating, over the course of a long project.
Earlier this year I spent about a week in several long conversations with Apple senior advisors where I even supplied them a sample of the project. The end result after they reproduced the problem on their end and tried to troubleshoot was that it was a problem in the program. They offered workarounds, but none better or less time consuming that dealing with un-linking manually.
It it helps, both projects were cut on brand new (at the start of the project) 8 core Mac Pros with 12 gigs + of ram and the two nVidia graphics cards, two monitors and an HDTV connected via DVI to HDMI cable as the 3rd playback screen.
Anyone else out there had trouble with these problems, specifically trim tool crashing, and found a solution?