Well, I did have 99.9% of my bases covered.
Immediately after I made this post, I noticed that the bind user pwd I had originally popped in got wiped out, so there was no password at all! Added it back in just now and bingo! All works nicely.
I'll put in the tracker a request to validate that form field.
Had I rec'd a message saying "You must provide a Bind User Password before saving your settings", it could have saved me a whole lotta' time and frustration.