PowerBook Display won't sleep

[Beej]

I have a PowerBook 3400c that basically runs SETI full-time. It's set up in my room, and I want to leave it run 24/7. I've set it up with a RAM disk and Peek-a-Boo, and it's crunching away happily. The thing is, the display won't turn off :(

It's running OS 9.1 and the display is set to turn off after 5 mins in the Energy Saver control panel. Any ideas?

[Durandal7]

Have you tried trashing the Energy Saver prefs? The file might have become corrupt.

[Choppaface]

if you're killing the finder with peekaboo then I dont think the energy saver extension can run properly like that