I researched the problem and found that BBC changed their stream source from Real Audio to iPlayer. The streams from iPlayer is compatible with yourmuze.fm.
Fortunately, BBC made a way to access iPlayer through the Blackberry. Point your Blackberry browser to BBC Mobile | BlackBerry Shortcut Applications
and download the BBC Mobile shortcut. When you click on the shortcut, it should take you to a browser stream source directly from the BBC instead of through yourmuze.fm.
Hopefully this works. I haven't tried it.