Apple may have had some trouble with its Mountain Lion redemption codes, which provide a free Mountain Lion upgrade to new Mac owners who purchased a system between June 11 through July 25 via the OS X Up To Date program.

Instead of receiving a code for Mountain Lion, some customers are reporting that they received a code for OS X Server instead. OS X Server, normally $19.99 in the App Store, adds filesharing and web services to Mountain Lion, but it requires the base OS to be installed first.

This redemption process has not been as smooth as Apple would have hoped. Some of the early codes did not work, some were for the server upgrade and according to reports on Twitter, some people are still waiting for their code to arrive.