So, I guess no one else is experiencing this problem...??

Upgraded to 610 - no change.

It affects all auditioning in the 64-bit version. I cannot audition RealTracks (in RT picker) or RealDrums (in RD picker) or Styles (in Style Picker).

It is NOT a problem in the 32-bit version. Would they be using different system components to play (audition) those thing in the 32-bit BIAB vs. the 64-bit BIAB???