Blue screen of death (BSOD)'memory management' randomly

I was having regular BSODs with a previous single 4GB memory module, and thousands of errors were coming up on memtest , so I returned it. These were all sorts of errors, and sometimes the computer would not boot. I have since bought two corsair 2GB DDR2 modules, however I am now having 'memory management' BSODs. It seems unlikely that these brand new corsair modules are also faulty.

This normally happens when I'm browsing the Internet, and never when I just leave my computer Idle.

I have already done a clean install, but the same thing is happening, also my bios version is the latest for my motherboard.

The new ram has large heat fins sticking out of the top, meaning I am forced to install the ram modules in ddr2 slots 3 and 4 as opposed to slots 1 and 2, as my heat-sink is too big. I plan to replace this with water cooling at some point, partly so I have space for more ram, but for now I want to get my computer running reliably.

The only other configurations I am able to do with this hardware, are one module in slot 2 and one in slot 4, and one in slot 2 and one in slot 3, both of which cause the computer to not even boot.

I have used speed-fan to monitor the temperatures, and they are all healthily low.

These are my computers components:

CPU: Intel core quad q6600 (2.4ghz)
MOBO:Gigabyte ga-ep45-ud3l
PSU:Corsair cx600
GPU: Radeon 6850 xfx
RAM:corsair xms2DHX 2x 2gb
Heatsink: themalright ultra 120 extreme
Case: Sharkoon T9
Monitor: Shimian QH270-IPSMS

I haven't done any overclocking, also I have checked the power management settings, and they are all correct for the memory (5-5-5-18 and 1.80)

Unlike before, other than these BSODs, I don't really have any other problems, my motherboard seems to function completely normally, booting every time(so long as i'm using slot 3 and 4), as does my power supply, fans etc.

I also have my resolution set at 2560X1440, although to me this doesn't seem relevant to me I guess it could be,



Please help!