I just love you!! You are such a wealth of knowledge!
The exact same clicking thing happened to me when I was IM training last spring. I took the bike in and the shop guy said my chain was bad.
I knew that they needed to be changed regularly, but I didn't know THAT regularly! OY! For a girl who put's at least 400 miles in a month, that's every three months (see I'm good at math too! )
Hmm... Now I'll have to start keeping track.
Good to know tho!