It's not working for me either after all. I replaced the system.ext with the one from 2.2 beta 2 and then it worked.
I've got the same problem as you:a white screen shows for a few seconds, and then the home screen shows.
Also, as I stated before, my google mail sync account has been removed, and I can't seem to re-add it. When I go to Gmail I get a message that the account has not been configured for auto-sync. Menu > Refresh doesn't do anything. Menu > Accounts shows "Gmail, 0 accounts". The Add Account button displays a black screen with "Add an account" at the top.