I have reproduced the following problem several times. I am running poclbm and phoenix through guiminer on Windows XP. The configuration does not appear to matter. I have a Radeon 6850 and have tried Catalyst 11.4, 11.5, 11.6, and 11.7.

I have two user accounts on a machine ("user1" and "user2"). the miner is set up to run under "user1". With "user1" still running, if the machine switched users and "user2" logs in, the miner (poclbm or phoenix) freezes. Task Manager also shows poclbm or phoenix at 100% CPU utilization.

Anyone else see this or find a work around?