Had an iPod nano 5th Gen but got stolen. Great for the gym could connect to Nike gym equipment and record my workouts. Replaced my iPod nano with 7th Gen but cannot seem to record my workouts anymore even after buying a very expensive adapter!!!

Had an iPod nano 5th Gen but got stolen. Great for the gym could connect to Nike gym equipment and record my workouts. Connected my iPod back into my home PC and updated my Nike+ webite with my times and distances. Replaced my iPod nano with 7th Gen but cannot seem to record my workouts anymore even after buying a very expensive adapter!!! Even stranger than that after giving up trying to connect the iPod to the gym equipment around Feb/Mar I can now see run data from June. What is going on?