Does it only freeze with your MKWii/SSBB? Try a different disc(borrow it from a friend.. etc.)
If it works with a different disk, you may have to buy a new one
i only freeze with MKWii and SSBB, I have tried with every game I got and only MKWii and SSBB freezes and it's only the game I have played in riivolution D:
I believe it's something about riivolution cause I notice MKWii got unreadable the same day I tested it in it, wanna test it with a other game but I dont wanna D;
and no, I haven't test with other MKWii/SSBB game discs D: I dont have any I can borrow ;_;