If you have some older crap files or live recordings like I did, you can download a program called Audacity and reencode the files at 128 kbps and update iTunes Match and it will read the files.
Good luck!
- Download Audacity here
- Open Audacity, then file open the song in question
- Click file export, then save the file either in a new location or replace the existing file.
- Make sure the new 128 kbps version is in iTunes (use the Summary tab in Get Info to make sure bit rate says 129 kbps)
- In the Store menu in iTunes select Update iTunes Match
Good luck!