I have recently upgraded my hp 6710b laptop from 11.04 to 11.10.
This is my developement machine so I have postfix installed as well as truecrypt that mounts my favourite volumes, asking me for the password on gui login.
Every time I enter the truecrypt password (even if the password is correct at first attempt) I receive a mail from the same machine telling:

3 incorrect password attempts ; TTY=unknown ; PWD=/home/xxx ; USER=root ; COMMAND=/usr/bin/truecrypt --core-service

The encrypted partition is mounted and works correctly, but this message is very annoying and didn't happen before.
I've read something about PAM problems, but don't know if this is the case,