Upgraded RAM - Machine slower and unstable. Help!

Here is my system:

Windows Vista Ultimate x64
Asus P5W-DH Deluxe mobo
EVGA 8800GTX GPU
Core 2 Duo Conroe 2.4
ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler

Just upgraded from 2GB of patriot memory to 4GB of Corsair. The Corsair I bought is:

http://www.newegg.com/Product/Prod [...] 6820145194

I went into BIOS upon installing (took the patriot memory out completely).

I set the SPD to 4-4-4-12-4. Gave it a shot and everything worked nicely. Slower boot but I figured thats because I had my CPU OC from 2.4 to 3.3 before with patriot. From what I can tell, the settings I have the RAM at are what is recc by Corsair.

Now, if I even try to take the CPU past 2.9 the machine is incredibly unstable. Didnt have any issues OC with the patriot. In fact, I even got the CPU to 3.6 but didnt like the temp so I kicked it back. CPU voltage is at 1.475 (Max is 1.5) and memory voltage is at 2.1. When I do OC I take it slow and try to maintain the RAM around 800MHz. With Patriot I was able to get it to around 900MHz, so a little OC but I took it back to 800.

Issues I have had:

-Sometimes the vista loading bar will just go on forever.
-Sometimes I get BSOD immediately upon entering windows. Last one was a BAD_POOL_HEADER error.
-Sometimes I get into windows and everything is just drastically slower.

Maybe I am just missing something? Please assist and thank you.

Hmm, my initial reaction was bad RAM but the MEMTEST returned negative...you could always try one stick at a time just to double check your ram is good...Other than that, I don't know...not much into OCing

Just tested each stick individually. Seems good to go on that side.

I did set tRC back to auto. I noticed that if I bump the timing to 5-5-5-12-5 in bios the machine allowed me to OC the CPU further. Sounds like that was the culprit?