Downgrades generally have to be done the hard way, archive and install followed by an update to the OS X version you want. This is the kind of situation that makes bootable disk-to-disk backups so popular 😱
Before you get into that, perhaps you could pull out all your third-party plugins, see if the problem goes away, then add them back one by one to see if one of them is causing the trouble.
Also, if you use anything at all on the system that relies on Application Enhancer, disable it. The Insanity people like to claim that APE is incapable of breaking things, but that's not quite true; anything loaded by APE certainly can cause grief. Anything that relies on SIMBL has the same potential to get in the way.