Are you on an apple computer and using the apple built in browser to play files?
Because SNES files originally come in 32KHz, and Apple's built in player (as well as iTunes) is incapable of correctly decoding 32KHz MP3 files.
I have thought about re-encoding the whole SNES section with an audio sample rate of 44.1KHz so that apple users can also correctly enjoy it, but oh boy are we talking about a huge hassle or WHAT. The whole thing is 118GB, and thats in 32K, re-encoded in 44.1K it would be even bigger. So its quite a fair bit of files to upload.