machine set to "auto-shutdown"?

[jay]

I am running Fedora Core 3 on a desktop machine for a while now.  The
only problem that I seem to be having is that after it has been idle for
a while the machine shuts down by itself.  Usually the screen saver will
kick in and be on for a while and then the machine will just shut down.
Other times I am working on the machine and it just shuts down.  I am
not seeing an error message and the machine starts back up just fine
without going through any of the "the machine was shut down improperly"
stuff.

Is that enough information for anyone to help?

thanks,
Jason