The login window that appears when restoring from a screensaver state does not include the ability to change keyboard formats. Necessary for those who routinely write in multiple languages.
I don't think you mean the session, but the login manager.
This problem happened to my wife today too. She types in Thai on her xubuntu (x86 32bit, ubuntu 11.10 with latest updates). But when the screen saver locked the screen, there was no way for us to get back into the session. I think the password was not being accepted in XScreenSaver 5.14 because of the input language in use prior to the screen locking. This is reproduceable every time. For example, when set to Thai keyboard before manually locking the screen from the User menu :- When typing the password, no asterisks appear, and when you press Enter, then password box showing "Checking..." then a message appears (in yellow) on a blank screen stating :- "assuming no password means cancel" "authentication via PAM cancelled" The only way I can find out of this, is a hard power-off and let the machine boot again. Trying to login via other users does indeed show English characters, but in this case, there are no other registered users, and it wouldn't allow a second session with the same user name that we were already stuck with. Pretty bad really. So I'm guessing that an input language switch is required on the XScreenSaver if at all possible. Any ideas who will be working on a fix for this, and when it might be available? All the best...
We don't develop the screensavers or login managers so we can't do anything about that.