To the OP, do you do a new search after posting?
For example, today when I got on the forum, I used "Today's Post" search request as the link to begin. You ask the forum for today's posts, and it generates a search based on that request, and it is assigned a number. This morning's result for me was "Search #2445770". If I start a new thread and then hit my back button to view "Search 2445770" and look for my thread, it will not be there (even if I hit refresh on my browser) because my new thread didn't exist when the search result was created.