I have a website, the URL is <theortegafamily.net> currently, and I use it for my music. I use the HTML5 audio player in the website, and you'll notice that on Firefox it works on the <theortegafamily.net/music.html> page, but not on the <theortegafamily.net/Our_Stuff/Nicolas/my_music.html> page. However, if you go to these two pages on Chrome, it does work.
I looked at the w3schools page on HTML5, and yes, I have all three audio formats there, you can even look at the code and you'll see that it's there.
So what I was wondering is if there's a simple way for me to just change the code on the website a little and it will work, or if it's a Mozilla problem and I'll have to wait for Mozilla to fix it.
It isn't the code, but likely caused because the media files are encoded with an unsupported codec.
In the first link the .wav file is played (right click: copy audio location) because the ogg file doesn't work and mp3 is not supported by Firefox.
If you want the ogg links to work you will probably have to recode them with the Theora codec.