When my PC is sitting at the gdm login, the screen blanks after 10 minutes and the monitor goes into suspend (screen powers down and powersave LED lights). But about a second after that, it wakes up again! Thereafter, the monitor oscillates between the 'on' and 'suspend' states every second. What might be causing this, and how can I get it to stay in the 'suspend' state? This happens after a completely clean install of RH8.0, with no modifications to any settings.

System:
mobo: Asus P4B (BIOS 1012)
graphics: nVidia GeForce 2 Ultra (using DVI-D, not VGA)
monitor: Eizo L365 LCD panel
os: Red Hat Linux 8.0 retail

I am having the same trouble with my monitor, plus it goes into power saving mode after 15 minutes when I am watching a DVD movie.
I read in several forums about passing apm=off and acpi=off to the kernal that meant editing /etc/lilo.conf the original lin had acpi=ht.
I just added noapic to the mix as well, it still goes off at 15minutes into the movie.
Amd XP2400
Asus A7N8X-XNVidia Riva TNT2/Vanta
monitor Viewsonic Optiquest
Mandrake 10.0
KDE 3.2

The system is called DPMS for Display Power Management Signaling System and the video card has control over it.

I never fixed this - I'm upgrading to FC3 soon, so we'll see what that does.

FC3 does the same - so I think it's just a hardware issue :-/