you might be trying to send Dolby pro logic data to the driver..

check your DVD software settings..

you can also try DVDgenie it might help set some sewttings you can't normally set in your software.

A PII 350 is not considered powerful enough to run DVDs in general.

You didn't write if you havea DVD decoding card installed but I think that combining a slow CPU with and ISA interface card is why you're experiencing problems..