Doug,
I have run into a weird situation in trying to load certain .mov files.  When I start Tracker and try to import those files Tracker hangs with a white screen.  I used Handbrake to convert that video to a .mp4 file but found that converted file will also cause Tracker to hang on start up.

By accident I found that if I go to the files location and then click on "open with" and then select Tracker it will open and run normally.  After tracking a point mass I then saved that project in a .trz project file and closed tracker.

Now if I start Tracker and try to load that .trz file it will hang again.  However if I go through the "open with" process for the video file Tracker will start up normally.  After the video loads I can  load the .trz file and get back my tracking points.

If you would like you I could send you the .mov file and the .trz file so you could see what is going on.

Thanks,
Gordon Judd