When I first activate a challenge I do see my name and challenge on the graph, but after a while it disappears; but the 'function icon' showing I have an active challenge continues to revolve around and around. If I still have an active challenge on-going, why does the graph spot indicating my challenge disappear on the graph after a certain amount of time?

Well here I am replying to myself. But despite a couple of dozen reads, no one has responded to this query. I really would like to know if my challenge is disappearing from the Challenge Graph. The little dot that represents my challenge (you know, you put your cursor over it and it shows me) vanishes after about 30 sec. but the waiting for an opponent animated feature still shows I am actively looking/seeking. I don't believe I have ever gotten a game once that little dot vanishes from the challenges graph. Please somebody tell me what's going on!

i've found that even thought the dot disappears the seek is active.  :)

Thank you! A response was much appreciated.

Sure!  At first I thought it was weird too, but now I know that as long as it says 'challenge issued' at bottom in the white box, your seek is live.  :)

Ah "You have issued a challenge". I also have a "Matching" just below the ratings box and a little animated icon going around and around.