I'm trying to setup a dedicated mining rig with 3 GPU's but even when I use only one GPU, the CPU jumps up to nearly 100%.  Here are the relevant specs...

Motherboard: MSI 890FXA-GD70
CPU: Sempron 145
Memory: 2GB

OS: Ubuntu 11.10
Driver: 11.12 x86_64
SDK: v2.6

According to what I've read elsewhere in these forums and on the web, both this particular CPU and motherboard are commonly used for multi-GPU mining.  Also, from what I've read, there was a bug with the ATI drivers recently that would peg the CPU, but the newer versions were supposed to have this bug fixed, and I've got the latest available (or so I think).

Does anybody have any idea why my CPU would be getting worked so hard?

Thanks!