This is a different error thrown by the code creating mysql.txt, this has also been fixed some time ago. The package that keeps getting installed is an old pkg and I'm not sure why it's not grabbing the latest one.
To get around this the easiest thing to do atm is edit /var/lib/dpkg/info/pluto-mythtv-player.postinst and add 'exit 0' right at the beginning of the script. Then apt-get -f install, which should complete. Then do a new update && upgrade to hopefully grab the latest pkg.