Comment 5 for bug 446591

Maybe this could also help, but i dont know.
"I don't want to suggest any command like "sudo update-initramfs -k all -c" without knowing exactly what I'm doing, since I don't know if a mistake could make your encrypted partition totally unaccessible."
(Source: http://ubuntuforums.org/showpost.php?p=7151878&postcount=5 )