0) Unity 4.01 worked fine on the latest OS X. 1) Got the update message and installed 4.1. (404 when trying to access the update url) 2) Unity doesn't work anymore. Freezes (Apple's spinning wheel) for seconds between each interaction/change/click/every few seconds in the IDE. 3) Deleted the new version and installed the old one, problem remains. 4) Deleted the old one and reinstalled the latest version, problem remains. Unity is in a unuseable state. Any ideas?