P5kC stuck at checking NVRam

[Guardian-Mage]

I had my computer since July and it has been working fine. I run Windows Vista and Linux and reboot every now and then to switch. Lately, I have been turning my computer off at night to give it a rest since I have not been downloading anything to leave it on. Last week, it got stuck at the ASUS logo. After powering down and back up and holding tab, I saw it was getting stuck as "Checking NVRam". I removed the CMOS Battery for 60 seconds and replaced it. It worked fine. Well now it happened again. I can't go screwing around with the battery every week. What could cause this problem?

Setup:
Asus P5KC Mobo
ATI Radeon 3870
4GB OCZ Vista Performance Platinum XTC 4GB PC2-6400 800MHz DDR2 Dual Channel Memory (2 x 2GB)
Intel Quad Core 2.4gHz
3 hard drives (80,250,500 , all sata)
All in one media reader (USB)
DVD Burner with Litescribe (Sata)
Thermaltake ToughPower (W0104RU) 650-Watt Power Supply

AND REMEMBER: It was working fine, and I hadn't made any changes in the BIOS anytime near when this was happening. Originally I had overclocked the CPU to 2.7, which is not a lot considering I have a Big Typhoon VX and a Full Tower ThermalTake Armor Case with a 25CM side fan and 5 other fans.

Oh, and the mobo was saying my ram was 733, but as soon as I went into the BIOS and restored to default it started saying 800 again. It still won't boot.

 

[Guardian-Mage]

I left it off all day (since 8:00, and it now 4:00) came home, pressed the power button, and it worked. If that helps any. Also, tech support said something might have failed, possibly the mobo. I am just going to leave my computer on forever now, and if it happens again I will probably take it to them as it is covered under my warranty