I just noticed I have the same problem (in PDVD13), the software refuses to play any MP3, WAV or other audio file when on HDMI output. It says the format is not supported.
But then I tried something. I also have an optical (TOSLINK) connection to my AV Receiver. So I switched PDVD to SPDIF and magic! The MP3 files work, as well as WAV files.
Now even more curious... if I switch back to HDMI mode while the file is playing... then the playback continues, on HDMI, flawlessly. If I stop and try starting again (while staying on HDMI), it once again says "format not supported".
There's obviously nothing wrong with my codec installation since everything works as intended in SPDIF mode, so there's definitely a bug in PDVD 13 (and obviously 12 too) about playing audio files via an HDMI connection.
I didn't notice this before because I'm only using PDVD for video and blu-ray, and use Winamp for audio, but I see how this can be annoying to people using it for an HTPC.
This message was edited 2 times. Last update was at Oct 14. 2013 09:11
My collection: http://www.blu-ray.com/community/collection.php?u=194008&action=showcategory&category=1&categoryid=7