Did you install the program from the disk? If so, check online for updates to the version you have. You should be able to Google the latest version of Action Replay Code Manager.
If you have the latest version, just sleep on it and try it the next day. If the AR still can't be read, then it's likely gone defective and no longer works. Action Replays have a tendency to malfunction easily, due to their fragile build. Sorry.