Photoshop :: CS6 Running Extremely Slowly?

So, I purchased CS6 when it was released and have been dealing with it's ridiculous speed ever since. It's gotten to the point where I can't tolerate it and can get no work done inside of it.
 
Basically, the main issue is the menu bar. I'll click on File or Image and have to wait at least 5 seconds for the menu to drop down. In the layer pallette I'll go to Alt Drag a layer and it'll freeze for a good 5-10 seconds, then reset and let me drag at will. Until I want to do another layer...then it does it all over again. Brushing occasionally becomes painfully slow and delayed. I used CS4 for years and never had these problems on the same computer. I work with extremely large files and am only having trouble with them after upgrading to CS6.
 
I'm running on Vista, yes I know. 6GB of Ram, so that should not be the issue. I do plan on purchasing a Mac in the next few months, but really need this problem sorted out Asap. I've googled endlessly and cannot find anything that works. I've changed drawing mode to Basic, disabled OpenGL, seemingly all of the obvious fixes, that haven't worked.