CPU Usage constantly at 50% during idle

[Vixe]

My CPU (AMD 6000+ BE) is constantly running at 50% usage. I've never seen it run below 40% since installing it on my system 3 weeks ago. Any idea why this might be?

Specs:
AMD Athlon X2 6000+ 3GHz Black Edition CPU
Asus M3A-H Motherboard
2 Gb Corsair RAM
GeForce 6600 GPU (Soon to buy the GTX 275. Was waiting for this release before buying a proper GPU)

 

[t85us]

i say, you have bad blocks on your hard drive. check them with hiren's boot cd (at least, in my case hdd regenerator solved the problem)

 

[Zenthar]

If you open the task manager, do you see which process is using the CPU?