Of the 25 MIR I have done since actively following this Hot Deals forum, an I/O Magic MIR for $20 is the only one to stone wall on paying up.
When I checked and then complained to their local Better Business Bureau, sure enough - complaints about rebates not being honored.
*** IF *** you want to insure getting paid, photocopy / scan absolutely everything, front and back, receipt, UPC, rebate form, ....
Make sure to follow up, probably repeatedly.
Good Luck.