Norbert, thank you for reporting this issue and working with us to make
Ubuntu better!
This bug in mysql-server-5.1.preinst, is mostly due to misleading error
messages. The script assumes because the mysqld init script exists, that
mysqld is in fact running, when it may very well not be.
The fix
** Attachment added: .etc.apparmor.d.usr.sbin.mysqld.txt
http://launchpadlibrarian.net/53073651/.etc.apparmor.d.usr.sbin.mysqld.txt
** Attachment added: AptOrdering.txt
http://launchpadlibrarian.net/53073652/AptOrdering.txt
** Attachment added: Dependencies.txt