It's the third day I'm mining there with 320 Gh/s and I still got no payouts. Is this normal or will it ever happen?
It's normal and at the same time not normal, but in a few words you should normally get paid once DMD is validated for trading at https://www.usecryptos.com/ and that should normally be tomorrow.
Basically the problem is that cryptsy has been having serious difficulties (to put it lightly) in processing BTC/DMD payments for well over a week now and since DMD was only listed at Cryptsy, payments were not going out. We are a few in the same situation.