Okay, here's what's going on. As of this morning my system was as follows:

AMD Athlon X2 5600+ @ 3.1 GHz
Abit AN-M2 Geforce 7025/630i
2 GB Corsair DDR2-800
MSI 8800gt OC
Western Digital Caviar SE 250 GB
Thermaltake Toughpower 700W Modular PSU

Today, I tried to add another 2 GB of ram (Corsair DD2-800, same as the other stuff). Unfortunately, when I tried to turn my computer back on, it wouldn't even post. I took the new sticks out and everything worked fine. After some testing, I concluded that all the sticks work fine and all my memory ports work fine as long as only three of them (3GB) are being used at once. But as soon as the fourth stick goes in, I can't even post.

I was hoping that someone could identify my problem and/or a possible solution.

Thanks in advance for your help.

Try setting higher voltage for RAM before You put all four sticks in

What OS are you using? XP and Vista 32 Bit don't work with memory above 2 Ghz and will recognize only 3-3.2 Ghz if you stick 4 Ghz. But they still will allow you to boot up. In your case, I really don't know why you can't even boot up your comp.

Try XP or Vista 64 Bit see if it works. Good Luck.

FYI, I once experience with Abit IP35 E board that doesn't compatible with Patriot DDR2 800 memory and also doesn't allow me to boot up then I replaced them with Corsair Twin2X 2048 PC6400 and it worked.

its probable the OC.

you memory controler is on chip and your working the chip already.

I found when OC I had to set timings to 2T to make it very far (even with memory dividers, so I think it was the controler, not the memory). If you're already doing that, loosen up your timings and see if it works.