John,

>For non-PUTM I'm almost sure the bottom messages don't drop off. You just miss them but then again, how can I test this. Seems silly, I'll just join

You can check by clicking on your "Replies" button now, and you should see this message at the very top (unless someone else has replied to you since my reply). Note that all messages in the Replies area are in reverse chronological order.

If you receive 49 more replies after this one, my message would be at the bottom. With one more reply after that mine will disappear from your list.