Mono recording from Audacity not playable?

[gomezz]

I recorded a football commentary stream on my laptop using Audacity.  Because of an issue with the stream the commentary was only on the left hand channel so I set Audacity to record in mono.  However when I extracted the audio from the recording as an mp2 file and copied to my Sansa Clip+ it would not play.  It played OK on the laptop using VLC.  Any ideas as to what is going on?

For now I will go back to setting the channel config on the Clip+ to LH Mono when playing this kind of stream recorded in stereo.