[nsvpl]

I had a very similar problem with the freeze frame and unable to navigate back to the main menu when I upgraded my media centre and installed a Sony Blue Ray reader and upgraded my video card to a Nvidia 9600GT. For a time I suspected the video card and tried various drivers. It even cut my link to my XBOX and I was unable to reconnect from the XBOX.

My Media Centre is Intel DG965WH MB with the disk configuration set to 'native' and 'RAID' in the bios setings. When I tried to load the Sony software for the blue ray my system crashed and went into boot loop mode. I figured there must be a hardware conflict for this to happen. So after a lot of trial and error and endless calls to Sony, I , by chance updated the SATA driver in device manager and now my Media Centre is back to normal.

I'm not sure whether this will fix your problem but it might be worthwhile downloading the latest drivers for your motherboard and update them through device manager.

best of luck
Gerry