Windows 7: Yep, another "stops responding" /"freeze" issue

Running Windows 7 Enterprise, 32-bit, I keep getting random freezes which last about 20-30 seconds, then the system always recovers. Generally, the mouse still moves, streaming music in not interrupted, but I can't do anything during these micro-freezes. CTRL-ALT-DEL is non-responsive at first, then once the task manager comes up, everything returns to normal. No abnnormal CPU usage. I have updated all the latest drivers, and have tried rolling back various component drivers to test it. Unistalled Avast antivirus and went with MS Security Essentials, and even installed the KB2265716 hotfix which described my problem. No luck. I have overclocked this system for several years with XP, but just to be safe, I returned all setting to factory once my issues with Windows 7 started. Still, no luck. Memtest okay. I did not have this issue for the first month of installing Windows 7. It has been about 2 months that I have had this problem. In addition, my screen goes black for a second (or more) from time to time. It is not the monitor. So it could be a video card issue. One more oddity, my power setting occasionally change on their own. The only one which does this is "turn the monitor off". It swithches to "20 minutes" every few days without me changing it. Event viewer shows nothing which helps troubleshoot any of these issues. I have not updated my bios to the latest, as I have read that people have had problems with the latest bios, and revision history really only deals with overclocking. I have scoured the net, so I realize that asking for a solution to such problems often is difficult as each PC can bring unique issues. But your help is appreciated.

Specs: EGVA 680i SLI, 2gb patriot RAM, radeon 4350, areca raid.

3 day bump...

see i am having the same problem. i have used 3 web browsers so far and ie and firefox does the same. google just crashes my computer