I was invited to create a ticker so I did (registered with the site about 4 weeks ago). It looked fine at first, but I've just returned to the thread in question and now my ticker is gone. What happened?? I'm seeing it again right after posting this. But is it going to get deleted again?

If you didn't have a signature in place at the time you posted in the other thread, then no signature will appear after you create one. It just affects future posts. I'm just guessing that's the issue, since I don't know what thread you are talking about

i cannot add a ticker to my account. there is no signature option in my control panel. can you give me some clue?

You cannot add a ticker to your signature until you have made 20 posts and have been here 20 days.