if you want to save the "uninstall/reinstall" as the last possible option try tossing out the PREFs (preference) file. usually when PS starts to act "wonky" tossing the file and forcing PS to rebuild a new one fixes up most probs. The files sometimes gets corrupted and can cause a number of unpleasentries!

you can delete it "on the fly" by holding down the Ctrl+Alt+Shift (MAC: Cmd+Opt+Shift) right after you launch PS. you should be prompted to "delete", let go of the keys and agree. it'll be rebuilt and the factory setting restored.

hope it helps
retrocity