I had the same problem but what I did was I deleted the tracks from my iTunes library on my PC from iTunes and iCloud. If u have your iPad connected to your PC this should also delete the tracks from your iPad as well. What I did then was I turned off music match on my PC then imported the deleted tracks back into my iTunes library. Which then automatically synced the tracks back to my iPad. After I had done that I disconnected my iPad from my PC and then turned music match on my PC back on. Then what that did was it went through the process of matching the songs I had just added to my iTunes library and then uploading the rest and artwork etc. It did the trick.
1- Delete tracks from iTunes library from PC and check box also delete from iCloud.
2- Turn off music match on PC
3- Import deleted tracks back into your iTunes library
4- Sync tracks normally (with iTunes Match off) automatically or manually depending on your settings.
5- Disconnect iPad from PC then turn music match on your PC back on.
6- Music match should then go through the process of matching the songs in the iTunes Store and uploading the rest etc.
Basically it seems to be that the problem is caused when u add tracks or albums to your iTunes library on your PC and then sync them to your iPad with iTunes Match on your PC on.