Where do threads go?

I saw it, then poof.

[pendanticist]

For better than a week I've been watching a thread in the Unanswered Posts. I'd seen this thread before, indeed, I believe I posted to it.

While I was watching that post slowly make it's way towards the top of the list, I searched for the thread I was involved in and could NOT find it.

Just a bit ago, the post I'm questioning made it to the top...then summarily dissappeared.

[Brett_Tabke]

Only the last 400 or so (about a day or two) are kept on the active list.