Please uninstall Lightroom following the article: http://helpx.adobe.com/creative-suite/kb/cs5-cleaner-tool-installation-problems.html and install again from the CC desktop app.
It worked up until the part where there was supposed to be a .log file created. I did not find one. Moving on, I reinstalled CC and the Lr app was still there but did allow me to re-install PS. frustrating. new IMac, new Mac user, but I need to uninstall Lr trial edition and I can't.