I got this error all the time :(
ERROR: KUniqueApplication: Can't setup DCOP communication
and the same if I try to start any kde app from any other desktop :(
Ive been trying everything Ive seen in the forums and no success chown .kde, deleting .kde socket tmp cache deleting iceauthority and nothing, one thing is I miss the file .DCOPserver_XXX__0 may be this can help to solve my problem?
(edit) one more thing I got as well "segmentation fault"