Windows 7: Random BSOD recently started, code1a, 3b and 50 by ntkrnlmp and win32k

I have a new build i started with last weekend to use as a htpc/file server, i put it all together and installed the os last weekend (no problems) and the updates and software throughout the week, i thought no problems, since then i have started getting random bsods and would like to fix it (i've had 4 in two days). I ran the windows debug tools but am new to this.

system dump and performance report are attached as per the instructions

os is windows 7 x64, i think it is an oem install disk (it is from another computer i bought a while ago)
hardware is new, gigabyte GA-h67n-usb-b3 mobo, i3-2105, 8gb corsair ram, 430W seasonic psu, stock cooler, etc, i know components are all compatible
os install is 1 week old with all latest updates from a few days ago, i looked at the performance report and should note i turn off automatic updates but tend to do this manually myself regularly when i want

thanks heaps to anyone who can help, i've already spent half a day before i found this site, great work



cheers

Trav