Tom thanks for the tip about using transcoding inside FCPX.
I think I have two distinct problems. The transcoding has made a huge difference, FCPX is now massively faster - and given what you and others have said about the native format the Canon 7D produces, I'm sure this was a big part of my stability problem.
However - I was disappointed after I've done the transcoding to find that the crashing (within seconds of opening FCPX) continued - but I've now found out how. My project consists of a series of clips separated by text titles - I've used the Chapter text title from the Bumper/Opener section that builds line by line. Although FCPX had been crashing after maybe 20 minutes use on a regular basis (hopefully from the clip format), I'd got to a point where whenever I opened my project and went to a particular section where I had inserted the Chapter title, I could click on the timeline, it would play for a few seconds, but if I tried to edit the text on the title, the interface would mostly stop responding. I could slill click on the different lines of text in the video window and the inspector would show the text in each, which I could change, but the video window stopped playing the video and the timeline stopped showing the current position line advancing - and there was no sound. FCPX would continue in this mostly unresponsive state until I killed it (tried quitting, but it would just sit there for hours not responding before I eventually gave up killing it).
This continued to happen (problem with the Chapter title on this specific transition from one clip to another. If I opened FCPX and deleted the title, then all was good - FCPX would close quickly, reopen and would work playing when I reopened. But if having deleted it, I put the title back again in the same place (where I want it!) then the hang behaviour returned. I can put titles elsewhere in the project (same title type) with no problems.
So for now I've just left a blank space in the problem area, and FCPX seems to be behaving perfectly as I work on other parts of the project. But I am confused about why I can't put the title in that problem section.
I saw a post about the Digital Rebelion app for checking clip problems and I've downloaded that and it reports no problems with my clips. I've also bought Event Manager X so I can turn off every single other project and event that I have so FCPX only has to work on the current project.
So mostly good - but if anyone has any suggestions about why the title keeps hanging FCPX in the one particular place but not everywhere else, I'd love to hear.
