wow....this thread/topic has lasted a long time. I have read most of all the comments. Here is my story 2 1/2 years later with no idea:
I have had the same/similar issue for 2 1/2 years now. I went to my ENT back then for it. He was able to feel the "click" when I swallowed which gave me a sigh of relief that I wasn't nuts. Upon visualization with a nasopharyngeal scope he found 2 thyroid nodules which turned out to be cancerous. I had a left lobe partial thyroidectomy. I thought I would wake from surgery to have the clicking gone. Unfortunately the click is still there. Finding the cancer was just a coincidence. My click has no pain associated with it. It just drives me nuts. As with most, I only have it looking straight on. It doesn't bother me drinking or eating. I am thinking it is not the hyoid bone because I have never had pain. Who knows. Will continue to follow this thread.