I haved some situation in my application where a page which used to be ok, stop working and calling my application and even sometimes crashes the whole application and would not get to a normal condition unless I redeploy the whole. I could reproduce it in dvd-seam application.
1- create a new user
2- enter your username and pass and go to the second page to enter information
3- give some invalid information, so the application gives you warning about the non valid information
4- now enter random username/password in the login dialog box at the right side of the screen. The application gives a nonvalid username password response at the same page
4- now enter the user info ( name sure name address..) and submit the left form of the page.
The application just refreshes the page without any action. Seems it is not entering the ENVOKE_APPLICATION phase.