I have had this problem, but it has been very specific to podcasts from NPR. Other podcasts and audio books have not been a problem. Have not downloaded any music.
I had some success when I used Windows Media Player (WMP) to ‘sync’ the podcast, but that stopped working last week.
I’ve only had this player for a few weeks, also used a Clip+ which also had problems with these files.
I’ve been working with Tech Support for the past 2 days and hope they will resolve the problem.