This is not a bug exactly, but it is something to be aware of. The XFree86 server has an option for DPMS (Energy Star) features. The DPMS states can be one of standby, suspend, off or on. Since the 2.4.x kernels cannot suspend to disk, this can cause problems. I fixed my system by doing two things:
xset -dpms (disables DPMS features)
In /etc/X11/XF86Config-4 I commented out
the line Option "DPMS" under Section "Monitor".