Some additional information:
PowerDVD version 7.3 ultra
SR Number: DVD090826-05
DVD version: 7.3.5711.0
Version type OEM/retail (was bundled but now full version from tech support)
OS Windows Vista 64 bit
VGA ATI Radeon 4680 512MB
Driver version: 8.661
Audio device M-Audio Delta 410 driver ver 5.10
Display connection DVI
Single monitor but logmein.com mirror driver
Antivirus software Avira Antivir
AMD Phenom Quad core, 6GB RAM
No error at all just will not play. When I click the Play arrow, the scrolling version info stops briefly then continues but disk never starts to play.
Your BD advisor now shows the ATI card as incompatible but it has been working fine for almost a year until the recent problem.
Is there a specific antivirus program you have seen problems with?
Thanks.