iTunes match is still rather new. Gotta give hackers time to figure out how to get it rocking.
I guess... I wonder if a fix will simply require a re-jailbreak or whether a full restore, then jailbreak will be necessary. Also, I wonder if iTunes is working fine for someone that doesn't have iTunes Match activated.
This only happens on the new jailbreak btw. My iPhone 4 (using redsn0w) doesn't have the same problem. Music player works perfectly fine.