Can you be more specific please?
Are you talking about sirius internet radio? I tried it on a guest account, and i had no sound on my desktop (even though it seemed to be fine).
I was using firefox under linux, so it may be that it uses some gimmick that doesn't work on linux systems
EDIT: see here. In their wisdom they decided to only support internet explorer and windoze media player. I won't go into a rant about why they utterly suck and people who push them should be flailed in the town square. Enough to say they won't work on anything not made by microsoft