Apple is fixing a problem with Mountain Lion promo codes that some users may have experienced earlier today.
Users who qualified for a free Mountain Lion promo code may have experienced an issue when they tried to redeem it this morning. The code was invalid.
The good news is that Apple is already fixing the problem and has begun sending out new codes. According to reports, the issue was the result of the tool going live a couple of days before Mountain Lion was officially released. However, website 9to5Mac received a re-issued code and reports that it worked perfectly for their system.