[Solved]Sporatic Audio Playback Possibly due to Faulty FX

This has only shown itself since upgrading from X3 to Platinum.  When I playback a set of audio tracks (there are more than ten of them) sometimes I get audio out of my speakers and sometimes I don't. Sometimes when I depress the space bar to start playing the track, it'll sound off for a few milliseconds ... then  quietness fills the room.  I can do this repeatedly and on occasion, the audio will playback properly.  It's intermittent.   Then again sometimes  a nasty "hiss-boom-blaring" signal emanates followed by low volume audio that progressively becomes what I would expect to hear.  
 
While troubleshooting, I found that bypassing the FX  in the control bar (up there with the master Solo Mute Record etc buttons) eliminates the problem. One at a time I've removed all of the FXs (three or four of them) and still the problem lives on. Even turning off all of the FXs by graying out the blue switch adjacent to each track doesn't seem to make the thing work properly.  Only when I bypass all FXs using the master button in the control bar does the  problem go away.
 
I must be missing something as I try to narrow down the problem to a specific FX.  Suggestions are welcomed. 
Boost11 was faulty!