Same for me with a GF3Ti500 (Hercules one)...
Everything seems to be ok when I look at the logs. The card works fine under XP and linux (same computer)... I had a few problems under linux to make it work, but using IgnorDisplayDevices "DFP, TV" made the work. Under Freebsd nothing helps :-(
Anyone has got a solution to get rid of this matrix like symbols & freeze ?