I can not to register at the pool digit.suprnova.cc.
What's the issue? I registered an hour ago and still mining without problem.
I cant register,too.Always said that the usernames are taken.
Did you leave the "Coin Address (optional)" field empty?
If so, try to put your wallet address on that field or some dummy text (if you don't have one yet).
You can change the payment address later.