Bug#373720: Listening to socket doesn't work

[Seiden Tiger <st@iss.tu-darmstadt.de>]

I was bitten by the same problem. It seems that after the upgrade of kde it 
tries to connect to the socket /var/run/cups/cups.sock:631 which fails for 
some reason. Setting it back to localhost:631 brings this thing working 
again. 

Translated from german thats "Control Center"->"Connected 
Devices"->"Printers"->"Printer management".

lsof shows that the socket seems to be open:

cupsd 19353       root    3u     unix 0xee6ae200     
40143 /var/run/cups/cups.sock

So it seems as if it's a kde problem? I am pretty shure that this happend 
after the update to kde 3.5.3.