Suddenly dropped frames for no reason

[Anton Silver]

Hi again,
Unfortunately nothing seems to work, I trashed the preferences file, nothing happened, I moved around files to another hard drive, same thing. I finally started to use my co-workers imac instead. With the same project, and suddenly… He has the same problem. Everything starts to drop frames, now he can’t open any project without dropping out frames. I really can’t isolate this problem, but It seems to start when you open this certain project, and then everything else opened after has the same problem. Something with these clips (Even If they are filmed with the same camera, and same format as I always use) that somehow screw things up with final cut… No one ever experienced similar problems? help :'(