After Standby login without password is no more possible

[UlfZibis]

I have 2 users installed:

A | Systemmanager | Login with password
B | Standard | Login without password

sudo passwd -Sa :
a P 08/25/2014 0 99999 7 -1
b NP 08/25/2014 0 99999 7 -1

If running under user B after some time the system automatically suspends to Standby, and is waked up later, at the normal login screen the login without password is no more possible, I get in red letters: wrong password.
Only change to another user and then logoff helps to again get to a normal working login screen.

[Tyler Hicks (tyhicks)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. We appreciate the difficulties you are facing, but this appears to be a "regular" (non-security) bug. I have unmarked it as a security issue since this bug does not show evidence of allowing attackers to cross privilege boundaries nor directly cause loss of data/privacy. Please feel free to report any other bugs you may find.

[UlfZibis (ulf-zibis)]

Added tag dataloss.
If user had some open documents and is not able to login after automatic screen-lock/standby, his data is lost forever, when user without administrator knowledge only is able to shut down his PC.