m4a podcast files can't be played by Duet?

I love listening to podcasts (Armin van Buuren, Tiesto), either as a downloaded file or as a stream. Unfortunately, these files are m4a's, which my Duet is unable to play. Switching to mysqueezebox.com won't fix this (it's supposed to increase the number of filetypes that are supported). Is there a way to make this work? Obviously I'm NOT talking about some tool to convert all my m4a's in a supported file format. I'm talking about some way to make my Duet play these files. My Popcorn Hour can play them, and so can DS Audio, my preferred streaming Audio app for my iPhone, so I'd be disappointed if my Squeezebox Duet would be the only one that fails.

Thanks beforehand for your reply.

Repelstale
The Netherlands