On one of my miners that was running Ubuntu 10.10, I ran updates against my better judgment (I just knew something was going to go wrong). Sure enough, after rebooting, I found that graphics weren't working properly anymore. I ended up having to restore graphics to default so I could reinstall the drivers. After installed Catalyst 11.9 and tried to run cgminer as normal, I was surprised to find that cgminer could only detect one of my GPUs. This machine has three 5970s in it, and all six GPUs were working just fine before the updates caused problems. I've tried reinstalling the drivers, version 2.5 of the AMD APP SDK, and using other miners, all to no avail. It appears to be a problem with OCL not being able to see all the GPUs that the ADL can. After each reinstall attempt and after running "sudo aticonfig --initial --adapter=all -f", I would be able to see the clock speeds and temperatures with --odgc and --odgt and even change clock and fan speeds using AMDOverdriveCtrl, but I can't seem to use the GPUs in OpenCL.