Memtest86 20k errors. PC BSOD at certain gaming points.

Hey, so...I recently built this computer. I'm actually on it right now. Specs that deal with this:

MSI 790X-G45
Ati Radeon 5750 HD
AMD Phenom II x4 3.4
Kingston 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Dual Channel Kit Desktop Memory Model KVR1066D3K2/4GR (link - http://www.newegg.com/Product/Product.aspx?Item=N82E168...)

Everything is updated, Nothing is overclocked. At certain points, Loading screen in L4D2, clicking "start" when I attempt to backup, and once or twice during internet browsing, the system has BSOD'd. Errors involved:

0x0000003b - 3 times
0x00000050 - 3 times
0x0000001a - 2 times
0x0000001e - 1 time
0x00000024 - 1 time

After trying to narrow the culprit down (updating all drivers, checking pc temp, installing Glary Utilities) I thought it might be the RAM. I downloaded and installed Memtest86 and let it run overnight. 20,000 errors by pass 11.

But...the pc runs fine 90-95% of the time. Sometimes it doesn't even crash. Newegg said they would refund or exchange by RAM. Which is fine, but, due to work and school (and Cataclysm coming out in a month   ) I cant wait 3-4 weeks without a computer. Forcing me to buy overpriced RAM at bestbuy  

Can anyone put my mind at rest? Assuring me that it IS the RAM and nothing else. Are there any issues I could of overlooked?

Thank you in advance for any help.  

-Z