[mythtvnz] Long delay when starting playback - possible fix

[Austin Green]

A few months ago, I reported a problem where starting to play a recording
would result in a long pause, around 30 seconds, with the screen completely
frozen, before the playback would start.  Recently I seem to have stumbled
on a work-round for the problem.

Every night a script is run, which essentially does this:
	mysqlcheck -c mythconverg -u root
If I run the script manually, just before starting the frontend,
then I don't get the delay on starting to watch a recording.

Looks like maybe a database corruption problem, although it never reports
finding any errors, just prints an 'OK' for each table checked.
Any clues from that as to what might be the root cause?