@sodahazy deadline is the number of seconds before a block is forged.
refer to http://www.burst-team.us/index.php/about/ for info on how poc mining works, see flow chart mapping out how a deadline is reached.
relevant here is that pool's set a target deadline and will not confirm a deadline which exceeds this. if your miner can't find a nonce with a deadline for the block within the deadline it either doesn't submit ('no deadline') or the pool replies with an error. no confirmed deadlines, no shares, no listing on pool web page.
again you haven't provided info so i am assuming here.