One other thing... even if I go to the folder on my computer that holds the demos (BB\RealTracks\Data\Style Demos Audio), if I double-click on a .wma file, it STILL will not play, if BB is still running.

Yes, this can mostly likely be fixed by unchecking the following setting* via Windows control panel:
Sound settings | Device Properties (Additional device properties) --> Advanced ..
"Allow applications to take exclusive control over this device"

*You might need to hunt for this setting as it seems to get buried deeper with each Windows update.
PG Music Inc.