System freezes "preparing to sleep"

Hello, yesterday I updated my suse 9.3 with opensuse 10.1 Since then the machine works for only max 5 minutes then it freezes. In the log I found: Aug 12 12:14:45 linux zmd: ShutdownManager (WARN): Preparing to sleep... Aug 12 12:14:46 linux zmd: ShutdownManager (WARN): Going to sleep, waking up at 08/13/2006 11:59:45 The waking up time is always 24h minus 15 minutes. I stopped zmd but the machine continues to freeze. Can anyone tell me how to stop this trange behaviour ? Thanks Andreas