CPU Peaking Out

I have all 3 of the 1.18.x viewers installed since windlight firstlook was rereleased, and am having issues with my CPU peaking out every minute on average which is extremely frustrating. The issue happens on all 3 viewers so is not limited to the RC or Windlight.

[img]http://www.overdrivenightclub.com/images/teds/systemcpuusage.jpg[\img]

The 'system' process gets as high as 80% however its difficult to take a screen shot as the whole PC is generally frozen. Note that SL suddenly bombs out in the CPU stakes when this happens. Sometimes I crash sometimes i dont. It doesn't happen using any of the multitude of audio and video rendering software i use just with SL. I have tried all the obvious avenues such as:

1. Clearing cache
   
2. Updating any and all drivers (video, motherboard, audio, NIC)
   
3. Reinstalling the client
   
4. Lowering any settings right down
   

All to no avail.

My system is AMD X2 6000+ (tried both dual core and changing affinity to single - also with and without AMD Dual Core Optimizer), 2gb ram, GeForce 6150, SATA drives, Windoze XP SP2 all applicable patches.

Whilst I acknowledge the video card is the weak link there it has worked fine up until the other day (and yes i plan on a new one shortly). I am at a loss of what else to try because any other time the "system" process uses next to no CPU whatsoever.

Any further ideas anyone?