Memtest86+ and 2 BSOD problem :S

Hello, i have recently built my new pc, and i have had 2 problems with the ram so far.

First time was 1 week ago or so, the same day i built and installed windows 7 and everything i got this image.



and i got this same image I THINK, yesterday but it was late at night and my mum called me and asked me and i was too tiered to read it properly but i thing its the same. Or believe so...


So that was 2 BSOD's.


Also because of that yesterday i was told to use memtest86, so i downloaded the memtest86+ version, dont know why... and i run that.

Here are some images.









After pass3 i just thought, no point running any longer, shows how bad this ram is doesnt it...

Anyways should i return it?

Also if i do return it, should i ask for a replacement, or ask for a refund and buy this instead?
http://www.ebuyer.com/229102-kingston-4gb-ddr3-1066mhz-...

because that one will have faster delivery.

thank you   Not too sure what to do, im using this pc right now, its running fine, just randomly did that BSOD twice...