My Travelmate has been shutting itself off nearly every time no one is signed in. There is nothing apparent in the Event Viewer. There are no Windows error messages when I turn the machine back on. It does not do this when someone is signed in. (Users may be logged in, but if the machine is left at the "To begin, click user name" window, the machine will shut off nearly every time after a few minutes or hours.) I experimented with being in and out of a login over several days, and it's very consistent.
The machine can be used all day long, with heavy disk usage or heavy CPU usage and it works fine, but leave it alone at the login window, and it justs turns off. I tried killing Acer's epm-dm.exe power management process, and this didn't make any difference. Acer hasn't been much help with this problem. They suggested going back to a System Restore point when the problem wasn't occurring, but I need every application I have installed and it started doing this recently. I haven't installed anything recently, anyway.