Since upgrading to IDEA 9 I've noticed that almost every 'operation' I perform, there is an annoying 1-3 second delay/freeze in IDEA before it allows me to do anything else. By 'operation' I mean every time I switch between files, switch between Find Usages views, type in a few characters, copy/paste text. It's almost as if some major processing is going on after I perform an operation (maybe IDEA is calculating the 'Undo' stack for the operation?). Whatever it is, it's making IDEA 9 unusable for me. I have a very large codebase loaded in IDEA (on the order of 10,000+ classes).
Is there a feature I can turn off in Preferences, or a Cache I can rebuild to make this fast again?