Can't say I know what thread you're talking about, but I'd just suggest adjusting your search parameters. Like if you can remember a particular member you know who posted in that thread, go to "find all posts by member x". Or perhaps if you can remember a particular word or phrase, even if it had nothing to do with the topic of the thread, it was just in the language of the discussion. And again, it might help to narrow the search if you remember what forum section it was in. You get the jist. Hope any of that helps.