I've got 10.8.2 and 2 users set up on it. One mine, wife the other. We've got seperate apple ID's. After she added her apple ID on her profile, I could no long do ITunes Match. Then I read that its because there can be only one apple IP per computer. Is this for real? It seems pretty stupid. Even Microsoft would not do something so stupid. If there is something to be done please let me know.
Yes it is for real, and no there is nothing to be done. Only one computer can be associated with an Apple ID for iTunes Match or iTunes Store auto downloads or to re-downloading past purchases. You'll just have to wait the 90 days.