I spent some hours trying to get my mythtv setup to schedule a few recordings that I had working using the subtitle matching feature to work again. Even tough the subtitles where exact matches it would not schedule any of them, and mark them as recorded. These showings where never recorded, so I got frustrated. What happens is, that if mythtv marks a showing wrong as Movie instead of TV Show and sets the ProgramID accordingly, then matching by subtitle never works. The only solution I could figure out was to reset the ProgramID for all the EPG data. This is done with the following SQL statement:
UPDATE `mythconverg`.`program` SET `programid` = ''
I found the reason why the above problem existed in my system. The XMLTV grabber I use (tvm2xml) often returns shows as movies. Mythfilldatabase then adds a unique programID to each show. This in turn leads to the above problem of not being able to record correctly. After I commented out the part of the script that adds categories to the XMLTV file everything is back to normal and I don’t need to run the above SQL statement.