compositing not working after upgrade

[Tim Folger <tf@timfolger.net>]

Hi,

I just ran one of my weekly upgrades last night (I'm using sid with the 
2.6.32-5-686-bigmem kernel). Now compositing no longer works with kde (4.4.5). 
When I click "resume compositing," I get a message saying "Compositing has 
been suspended by another application."  glxinfo | grep render says direct 
rendering is working. But when I run glxgears, I only get text output, without 
the animated gears. 

My middle mouse button also stopped working after the upgrade, i.e., I can't 
use it to copy and paste; can't open new tabs in any browser. (The mouse works 
perfectly in my other two computers, both of which still have kde 3.5.10 
installed.) I'm using the radeon driver. None of these problems existed before 
last night's full-upgrade, so the upgrade definitely broke a few things, and I 
don't know how to fix them. 

Thanks for any suggestions...

Tim