Can't view DVDs using Radeon 9600SE
I recently installed a Radeon 9600SE by Sapphire Technologies on my WinXP system (P4 -1.5GHz). The installation went fine and everything else looks okay, but I can't view DVDs anymore. What basically happens is when I insert a movie I can hear the audio but the screen is blank. This happens regardless of whether I use WinDVD or InterActual. I can still view regular video files with no problem (.mpg, .avi, etc.) and games perform well too. It just seems to have a problem with DVDs.
My resolution is set to 1152 x 864, but it makes no difference if I change it to anything else. I uninstalled/reinstalled the software and I updated the Catalyst driver from 4.1 to 4.5 (downloaded directly from ATI); no luck. I also checked the primary and secondary channel controllers to make sure the transfer modes were set to DMA, which they were.
My previous card was a Radeon 7000 and DVDs always worked fine with that. In fact, if I remove the 9600 and reinstall the 7000 with its original drivers, I can view DVDs again.
Do you have any idea what's causing this and how it can be resolved?