Won't play streaming audio on websites

My mini has a problem recently. I visit some websites, especially myspace(lol, I'm a teen so no jokes!) that have streaming audio in the background. My problem is that it will never play for me. It's nothing wrong with the coding or html on the people's myspaces, it's my computer. Maybe a settings or something? Is there a quick fix, or does anyone know why my mini won't play sounds from the internet? It's so annoying. I have no sound when watching streamed mpegs from different websites, or videos on youtube, either. Anyone know what's happening?

its more then likely the windows media player not playing it, my wifes brother has the same problem when viewing profiles on myspace from my mac.

is it windows media player like stated above, or is it the music player that is part of myspace (flash)

It happens on myspace with the default myspace player, and any youtube.com videos I watch, Cnet videos, everything. No sound. It's not my speakers, by the way.