That bug has been reported for the Schedule Library as well. Once the interface is maximized, the underlying entry windows are hidden.
When you close the full screened window, the smaller windows are still there. If you attempt to close the small windows or exit the greyed over Session editing screen, there will be a CTD.
I'm going to try the brute force DBR and see if that works.
Sadly, the brute force DBR didn't solve the problem. Once maximized, the interface remains that way.