Toshiba 1612 DVD not recognizing disc

Is there a fix or patch?

I'm running PowerDVD XP with Windows XP Pro.
I keep getting an error on some of the DVD - this is not the correct format for windows. The dvd will play on other home dvd players.

Region set on 1
Unlimited - mean not restriction.

Any help will be appreciated

System -
1.6a P4 o/c to 2.1
512 ddr memory
ASUS p4b266

what dvd are you putting in it? Have you tried a domestic release DVD and does it work?