Clips exporting as black with 10.0.7

Has anyone had problems with the latest update exporting black instead of a clip or pic? I've tried deleting the offending part and re inserting it but then a different part is exported black. Pretty furious as I have to spend half a day each time to find out if it's exported correctly.

Cheers,
Nigel McGuinness

maybe you forgot to take off the lens cap from the camera...