Display power control stops working

I have a PC with an AMD Athlon 64 +3500 chip. I have two hard drives with Debian on them. The 80G drive has "sarge", i386 port updated to unstable as recently as 12/15/07. The 160G drive has "etch", amd64 port, updated to current unstable (12/22/07).

On both systems the KDE display power control stops working after a day or so (the screen no longer goes blank). If I restart X or modify the Power Control settings through the Control Center, the power control starts working again (but only for a day or so). The power control settings are kept in ~/.kde/share/config/kcmdisplayrc (not a root account). If I modify this file using an editor, the power control does not start working again.

What is the problem?

-- 
To UNSUBSCRIBE, email to debian-kde-REQUEST@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmaster@lists.debian.org