dan:

Is your computer connected to the internet?
When I open the RealTracks picker and select an entry in Set 77 (say RealTrack 940 Piano...),
then press the (Play) Solo button, a yellow "information" box pops up in the bottom RH corner of the screen
stating that it is accessing a .wma file from here

http://demos2.pgmusic.com/pgmusic/audio/realtracksdemos/940solo.wma

That file isn't in my bb folder.
Good Luck!
LLOYD S