Blackberry Podcast

1st of all, this is my fav program on my BB. Keeps me up to date with all the podcasts that I want.

However, recently I have had a problem with a few selected podcasts that will not play when downloaded. I get this following message -

The media file "....(Media File Name).................."being played is of an unsupported format.

I can delete the 'cast and as it is re-downloading I can preview it, but this is a pain!!!

I have re-downloaded the file, but to no success - any ideas what I can do?