Hard locks ?memory issue

[pert_of_jb]

Hi All,
I have been issues with World of Warcraft for the past 6months really...! I get random, erratic complete system lock ups which require a manual restart. There is no associated error message. These lock ups will occur *generally* anywhere in the loading process from just at the welcome screen, to up to loading of the game world. I've done the usual updating of drivers / removing addon / reinstalling, so I contacted Blizzard and they suggested running Memtest.

So tonight, I rebooted my system and ran memtest, and it caused my system to restart after about 5seconds (around 50% of the way through the first test).

I proceed to then open my case and realised (stupidly) that my DDR2 twin modules were not in dual channel mode. So I moved the two modules into the correct alignment, upon restarting I was then presented with numerous different BSOD, highlighting files such as ntfs.sys and dxgmms1.sys causing page errors.

I then proceed to test each module in each slot. In isolation they all seem to work ok, although WoW still locks up. I haven't as yet put the two modules back into the slots at the same time.

I am after some advice really.

Firstly I had hoped to find something wrong so I can get the issue with WoW sorted, so any further suggestions here would be appreciated

Secondly - am I confused how the memtest crashed when both modules were in place, but can successfully scan each module in each slot.

I have some old RAM is it worth trying that???

Specs:
Motherboard - Gigabyte - EP45 UD3L
RAM - 2x4096 - 6400C4DHX DD2 Corsair
Intel Quad Core 9550
XFX Nvidia Gefore 8800 GTX
Sound - Realtek onboard card OR Soundblaster XFi Xtreme Music
Windows 7 64 bit

Many Thanks in advance

 

[pert_of_jb]

Just an update - i've put my twin modules into dual channel mode (i.e. DDR_2 and DDR_4) and it seems to be working, not tested anything but firefox though...