Synchronize files question

Hi, I’ve had this problem but initially had the error where my clip suddenly wasn’t recognised by my pc.  This is how I finally overcame the problem and I seem to be back to normal:changed USB mode to MSC (my pc then recognised my clip), upgraded the firmware, (better but now I got the sync files problem), moved to my laptop that COULD see my clip in MTP mode, upgraded the rights on my music files in Windows Media Player (I couldn’t see this from my XP machine, only in vista on my laptop), resynched in MTP mode, refreshed the database and now all is fine.  I have to say that this sounds straight forward but it took me five sessions to get this far…  hope this helps.