I'm (or more accurately my brother) having a problem with my Power Mac G5 (see sig). Often when my brother logs into his account, he works for a minute or so and then the machine goes to sleep for no apparent reason. He insists that he's not doing anything out of the ordinary, just using Safari, and isn't bumping the power button or anything like that. Any ideas on what could be causing this? The machine is running an up to date 10.3.9. The problem NEVER occurs for me using my login, so I really don't think it's a hardware problem, and figure it must be a software issue. I use the machine a lot more than him, for a lot more intensive work, and I figure that if it was a hardware problem, I'd see it happen at least as much as he does, but like I said, it's never happened to me even once. I've tried to check the logs, but I'm not really sure which logs to check. One of the system logs reports the sleep events, and I can see that wake from sleep (before he logs in) and a subsequent sleep event are minutes if not seconds apart, but there are no errors that I can tell reported in the same log. Could it be some background process that is unique to his login? The system is unmodified, no haxies or anything like that, and he doesn't really use anything other than Safari. There are no special peripherals hooked up to the system, just the Apple monitor (CRT studio display), Apple keyboard, Microsoft Intellimouse Explorer, and Maxtor firewire hard drive. Any ideas?