My MiniMag II (IDMB-XXXXXX) sometime returns incorrect data. If you suspect this is happening to you, should test for it in notepad by repeatedly swiping the same card. The reader should return consistent results. If instead you find A) there are sometimes missing character(s); B) There are extra characters or C) One or more characters have changed, you may need to adjust the Polling Interval setting. Basically this setting will slow the reader down a bit which may be necessary on certain computers. The instructions below show you how to use the MagSwipe Configuration Utility to change the setting. the default value is 1 this is the fastest. Increase the value and do the same test in notepad to discover the optimal setting for your host computer. Try setting it to 5. Anything higher than 10 is unlikely to be effective.