FS9 Crash/Freeze

I recently upgraded to the new ATI 5.5 display drivers and this morning FS9 froze on me while flying to Whigby NAS from KSEA. I had to turn off the system and restart. I checked the event log (Administrative Tools/Event Viewer/System) and found the following error message: "The driver ati2dvag for the display device devicevideo0 got stuck in an infinite loop. This usually indicates a problem with the device itself or with the device driver programming the hardward incorrectly. Please check with your hardware vender for any driver updates." It also showed the Source was ati2mtag and the Event ID was 108.I fixed this problem by manually reinstalling the ATI display drivers (Device Manager>Display Adapters>selecting the device and then clicking on Update Drivers>and installing from a specific location and then locating the proper INF file in the ATI directory - cx_22511.inf). This reinstalled the drivers.I recommend anyone having a crash/screen freeze check out their event viewer and see if the ATI drivers are at fault, and if so, they reinstall the drivers manually as I did above. FYI, I did uninstall my old drivers before I upgraded to the new 5.5 display drivers. I also used the Drive Cleaner Program. It appears a registry entry is not made when installing these drivers as my system indicated the drivers were properly installed, working properly and were the correct version.Hope this helps any others who may suffer a future FS9 crash or their screen freezes.Jim