Aha, the great mystery of ImageMixer that few realize: When you select an individual file in ImageMixer and convert it to MPEG2, it CHANGES THE AUDIO to MPEG 1 Layer 2, a non-DVD compliant audio that all PC programs can play. If you just put a mini-DVD file into an ImageMixer album (thereby copying it to your PC), the Dolby Digital AC3 audio is left unchanged. If you edit your mini-DVD files in ImageMixer, it converts the Dolby Digital AC3 audio from 256 Kbps to 384 Kbps, but leaves it in the AC3 format. So you could still have an AC3 problem.

If the mini-DVD plays in a standalone DVD player, than your PC is incorrectly configured in some way. For some reason, it may not be able to play DVD's even though you have the hardware and software to do so.