I had encountered the exact same problem a day or so ago. The fix actually lies in kdelibs, and is available in SVN revisions r1170159 and r1170194. You will probably have to update and recompile tqtinterface before kdelibs can be updated and recompiled due to a couple of changes that were made for Qt4 compatibility
Hmm. I had some suspicions when I updated svn today and saw the tqtinterface updates.
Okay, back to square one!