can't shutdown or log out from kde 4.4.5

[Tim Folger <tf@timfolger.net>]

I just installed debian unstable with kde 4.4.5 on a new hp desktop. 
Everything is working fine except when I try to logout or shutdown by right 
clicking on the desktop. No matter which option I choose--logout, shutdown, or 
restart--the screen goes black and nothing happens. I'm forced to do a hard 
shutdown or use alt-SysRq-B to reboot. I can reboot or shutdown using the 
command line when logged into kde. Is anyone else having this problem? Any 
ideas how to solve it?