rogue suspend is driving me nuts

[brian]

2.6.29.6-217.2.16.fc11.i586

For the past couple of weeks, my desktop machine has been shutting down 
on its own. I thought it might be a hardware problem until I noticed 
that, each time, /var/log/pm-suspend.log was being written to:

Initial commandline parameters:
Mon Aug 31 12:53:31 EDT 2009: Running hooks for suspend.
/usr/lib/pm-utils/sleep.d/00auto-quirk suspend suspend: Adding quirks 
from HAL: --quirk-dpms-on --quirk-dpms-suspend --quirk-vbe-post 
--quirk-vbemode-restore --quirk-vbestate-restore --quirk-vga-mode-3

... etc.

So, what the heck is driving this? Can anyone tell me what is calling 
/usr/lib/pm-utils/sleep.d/*? This box is quickly becoming unusable.