Using Norton Internet Security Suite 5.1.0.29 with Constant Guard from Comcast. When I let my computer idle, it started locking up (cursor moved, but could not ctrl-alt-delete and get a response) requriing a hard reboot. I set Nortin AV to silent mode for 1 day, and that solved the problem (sort of) until today, when it locks up after 10 minutes of idle. On the plus side, my system is running wildly faster without Norton background tasks running.
Running Windows 7 Home Premium