When using my 12" Powerbook to create VCDs or DVDs from "Standard" quality ReplayTV files, the bottom half of the resulting product is blank.

If I use "Medium" or "High" quality ReplayTV files, this does not happen. Also, if I move the MPEG-1 or Standard quality file to my iMac and then create and burn, the problem does not occur.

I have come across one other person, who notes a similar problem with his 12" powerbook.

Any ideas?