About a month ago, I purchased the following..
 
GA-P35-DS3L
Crucial Ballistix 4GB(2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400)
XFX PVT88PYDF4 GeForce 8800GT 512MB 256-bit GDDR3 PCI-e
CORSAIR CMPSU-550VX ATX12V V2.2 550W Power Supply
 
After getting it all setup, I went towards overclocking.  I got it to a stable overclock and it ran for about 3 weeks until I started getting random blue screen errors, to where it wouldn't boot Vista x64.  Eventually it got to the point where it would reboot and auto recover the BIOS from the HDD, and loop about 10 times, until the board went dead and wouldn't POST.
 
I cleared the BIOS, did everything I could, but it would not post.  Got an RMA and 2 weeks later, I got a replacement board.
 
Replaced it, booted it up, everything runs fine for a day.  I don't do any overclocking of the motherboard (video card is still overclocked), just change some of the default BIOS settings to enable USB keyboard, etc.
 
I start getting blue screen errors, always the same one.. IRQL_LESS_THAN_OR_EQUAL -- from my reading it looked like a driver problem.  Reinstalled every driver for every device, still got the error randomly every several hours.  Just happened before this post, and damnit, it went to the BIOS auto-recovering screen again and luckily, after 6 reboots, it booted back up retaining all my basic BIOS setting changes.
 
What is happening?  I tested the memory with the Windows Memory Diag, and with MemTest86, no errors.  Is it that my power supply is too weak?  I have 3 SATA HDDs, 1 DVDRW, 3 120mm fans, 1 small hdd fan, 1 8800 GT PCIe (overclocked), and the led on the front panel.  I'm afraid to leave my PC on, scared that in the morning it won't boot again.  Is that too much of a load on the PSU?  Should I get a 650w or 750w?
 
Any help or suggestions would be lovely.  Thanks guys.  

Thats an odd one, alright. Did you try and just replace the bios with a fresh one? Or even an older one, just to see if that stops the issue?
 
Your power supply is a little weak, but it should'nt keep causing problems if only the card is OC'd. I dont thing. (You'd have to check the rail strength and such on the side of the power supply. Most have their power to whatever plug.)
 
Maybe you should just stock everything and see if it persists? Then you'll know it was something to do with the video card, and not other things!
 
--Lupi

Well, I have removed the overclock on my video card.  So, everything is stock.  I'll guess I'll find out in the morning.

Welcome to the world of overclocking
 
reset it all to stock speeds and manually set all the memory timings and voltages in the bios and see how that goes for about a month.
 
BTW that 550w is sufficent aslong as its in good working order.
 
Got any spare parts (or borrow etc) like ram or psu's you can try?

Well, woke up this morning with the blue screen, and now my PC won't boot up since the motherboard won't post.  When I hit the reset button, my PC started up, turned off, and started up again.. and nothing.
 
I barely had this motherboard for a day.  Now the PC starts up, I get no video or anything.  Nothing was overclocked on this board.
 
This is so frustrating.

Just another quick update..
 
After 7-8 resets and it not posting, I unplugged the power cable from the power supply, plugged it back in and booted up.  
 
It went back to that "BIOS" auto-recovery screen, and after 4-5 attempts, the BIOS was recovered and now my PC will boot again.
 
The only thing different now is that I unplugged 2 of my HDDs.  This is growing tiring.  Should I attempt to flash the BIOS with a newer version (current running F7 which it came with)?

Wha?? Hell yeah you should! You have an initial release bios? LOL!

That could be the source of all your trouble! newer gear that wasnt common when the board had its initial release!!
See where it suggests, back up there a few posts, that you should?

--Lupi!

Well, I've updated my BIOS to the latest version.. still getting the IRQL_LESS_THAN_EQUAL (0x0000000A) error, and sadly it doesn't tell me what it causing it.  Then, it will reboot.  Seems as if it sits at that screen for too long (ie. I go out and come back it crashed) it goes through the BIOS auto-recovery thing, my PC does the 4-5 reboots, and it boots up again.
 
So, now I'm going to let it idle in safe mode, and see what it does.

Ram needs more voltage. And timings probably need set manually. After you get the volts and timings fixed, run memtest86 for 8 hours. If you dont get errors you should be good to go.

 
Hmmmm sounds almost as if the psu is having cold start issues and troubles sustaining the required power, long shot there tho...

 
Agreed there, memory for performance machines need to be manually configured, and could also be the cause.

Well, I upped the voltage to 2.1v (it's rated at 2.2v) and it has been stable ever since.  Thanks for the suggestion, thought it was safe to assume the motherboard knew what voltage to put it at.
 
I didn't change the timings however, going to wait a bit.

 
Performance ram and motherboards never get along these days - manually set everything to be sure
 
My old ASUS P5B Deluxe Wifi/Ap tried to use my Corsair C5's (C5-5-5-15) @ 4-4-4-12 limiting my overclock and cause chaos - configuring it manually fixed everything and allowed me to break the FSB1600 barrier with an E6600

I agree as well.

---------------
E2180 @3.2Ghz + P35DS3L +8400GS (700/475 OC)  

Also checkout:
GUIDE: Overclocking On P35-DS3L

---------------
E2180 @3.2Ghz + P35DS3L +8400GS (700/475 OC)