I'm checking out FC5T1 and notice that gnome-screensaver has replaced
xscreensaver. However, gnome-screensaver doesn't have any options to
enable DPMS, and it *disables* the xserver DPMS setting, e.g., if you
execute...
$ xset dpms 300 300 300 # shutdown display after 5 minutes
DPMS monitor shutdown will take place as scheduled, but
gnome-screensaver disables it when it kicks in (doing the equivalent of
'xset -dpms'). (Same thing happens if DPMS is enabled in the xorg.conf
file instead of through xset).
--
Chris Tyler