Overclocking Failed!

I have this mobo:
ASUS P4S800D-X 478 SiS 655FX ATX Intel Motherboard - Retail

I have this RAM:
CORSAIR 1GB (2 x 512MB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Dual Channel Kit Desktop Memory Model VS1GBKIT400 - Retail

I just added this RAM:
Kingston HyperX 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Desktop Memory Model KHX3200AK2/2G - Retail

Now I get an error message when booting my machine about "Overclocking Failed" It gives me the option of entering setup or proceeding with the default BIOS configuration.

When I proceed with the default BIOS config, the machine boots fine. But, when I boot again I'm right back to the same error message and prompt.

So, I entered the "setup" aka BIOS...and everything looked correct to me.

I haven't changed any BIOS settings...I'm running BIOS ver 8.00.09

Any suggestions would be appreciated.

It works fine with just the 2 x 1GB Kingston in there.

How do I get the 2 x 1GB Kingston to work with my legacy 2 x 512KB Corsair?

Is it a volt issue?
Is it a timing issue?

How do I figure out what the right settings are? Obviously it's a BIOS thing right?

HOORRAAY! Fixed it.

I read on some post somewhere about a guy changing the CAS from AUTO to 3.

Well in my BIOS I changed the CAS from "BY SPD" to "3T" and voila. Now I'm cooking with gas!

ARRRRGGGHH! Spoke too soon! Everything seemed fine. Then I decided to run memtest86 to verify everything was on the up-and-up. Yea, not so much! I don't pretend to understand memtest86's output screen, but I'm guessing the Pass=0 and Errors=1398754 and counting aint good!

So, now what?! This is so frustrating! I know enough about hardware to be dangerous! According to that error count...I'm very dangerous at the moment!