Let me try understand the problem. Your guide data is wrong for a couple of channels? But you can play the channels and they show correct programs?
If that is the case, and you use one of the xmltv options (i.e. not over-the-air option), I would suspect that you had the xmltv ID association wrong. Try running EPG scan manually, and at the last step check the xmltv ID association and make sure they are set correctly.