Were any frames dropped during capture? If NOT then can you send me a short sample of the clip. Email address is in the signature. You can use https://www.yousendit.com to send me the problematic area.
a) What is the source of your video and audio clips?
b) How large are your still images?
c) Does the project crash when you are NOT using the AE projects?
d) Are you running any background processes?