MP4a audio not working in videos (1 Viewer)

[Topher5000]

I have a couple mp4 videos that have mp4a audio. In MediaPortal, the only audio that plays are the left & right front channels. In Media Player Classic, the audio works fine & my receiver shows 5.1 channels.
Is there anything I can do to get MP to play the audio correctly?

 

[Topher5000]

solved

After some sleuthing, I figured it out.
I opened the videos in G Spot to check the audio format & it was AAC MP4A. I then went to videohelp.com, checked the codec tools & found that ffdshow supports AAC. So I went to configure ffdshow audio & found that it was disabled. Changing it to whatever the other option was (I can't remember) fixed it.