Just some info. Not too long back, I mistakenly changed the permissions of my Home Folder to read-write for everyone, and I clicked 'Apply to enclosed items'. This screwed up my ACLs, and I subsequently couldn't copy paste, drag drop, and spotlight wouldn't startup on its own. I resolved this issue (quite simply), and I hope this helps someone who's stuck in a similar situation. Open terminal.app (in /Applications/Utilities), and type: sudo -s (type password) mkdir /tmp chmod -R 1777 /tmp logout, login, and that's it.