thread not showing under active posts.

[Charlie B]

I just replied to a thread, and it no longer shows under view active topics, I reposted using the back button, and that post showed as a duplicate but when I returned to the "view active topics" the thread still doesn't show. I can find the thread by going to the posters user name (a newbie I wanted to welcome) but then it still doesn't show. I wonder if there are more threads that have disappeared from me.
Charlie