Hopefully you got it working. I ran into the very same problem and I'm not a neophyte. Here's what I did to resolve it:

1 - put the MP3 audio files into the My Music folder. Do not try to organize them with sub-folders etc., won't work...and you won't be able to access your music

2 - ensure the files are Stereo and not Mono...my mono files didn't work

3 - convert your MP3's to 128kbs using whatever MP3 software you like (I used Adobe Soundbooth).

That solved the problems for me.

Best of luck.

I see this thread is a bit old but I'm having the same problem. Audio files are 128k mp3 and the 'play' button does nothing. Any other ideas.

Thanks, Dave

I solved the problem. The music I was trying to play was stored on the nook memory card, not main memory. The audio tool would list all the music files on the memory card but the play button just wouldn't respond. I then transferred some mp3 files from my PC to the nook main memory. The nook then saw only those new files and played them ok. The files on the memory card were no longer listed. My next step was to re-boot the nook. After it restarted, all music files in main memory and storage card memory were listed and all played just fine. I then moved the music files from main memory to the storage card and again, all files were listed and played fine. The key seems to be in re-starting the nook to get past some problem in the software. Hopefully, this might help other nook users that have similar problems.

Dave