I reinstalled the driver and now GLX is being correctly loaded, however the behaviour is still exactly the same.
I have tried BIOS versions 3.3 and 9.3 from the following MSI url: http://www.msi.com.tw/program/suppor...UID=608&kind=1
I tried with NvAgp "0" however all it did was make it lock up sooner, once when I tried to start a doom3 game and then again while glxgears was running.
I will try with the 1.0-9625 driver next and see if it has the same behaviour.
I have used the 'nv' driver for a while in the past couple of days and never noticed any lockups or any other problems apart from it being painfully slow.
I have attached the bug report logs for my 5200 card which is working perfectly fine and the 6600 card which is experiencing the random lockups. These reports are from after fixing the GLX loading problem.