i have the same problem (406 error) trying to access .mp3 files from my googlepage. blackberrylive.googlepages.com
but.....
when i use yahoo briefcase it works fine.
so....
i would guess it has something to do with the site hosting the .mp3 files.
downloading images from googlepages works fine, its just the .mp3s that hiccup the BB. not sure why and i would LOVE if someone could tell me.