mythbackend hangs with error "MainServer: Unknown socket closing MythSocket"

This error seems to occur every few months. It will also take down XBMC To fix it:

1. kill -9 xbmc 
2. sudo service mythbackend stop
3. sudo service mysql stop
4. ps ax|grep mythbackend
5. kill -9 all mythbackend instances found
6. sudo service mysql start
7. sudo service mythbackend start

Finally restart XBMC and rock on!