I'm not sure why mustang has not addresses this but tntmining is closed for all intensive purposes if you want to mine on the pool that's up to you but unless it solves a block you wont get paid , as you can see from the front page of tntmining.com it's still set to pplns.
Tntmining was basically an experiment for him and if you wasted shares there I feel for ya man , no one wasted more shares than I did, I told mustang to lock this thread change the topic and close it down several days ago but for whatever reason he has not gotten around to it yet.
There are nothing guaranteed with tntmining and I think you should not mine there even if it still appears to be open , it is a ship with no captain, so beware or you could be the one to go down with the ship