All pool operators were asked to change max diff to 9999 to stop Nicehash. And all did. Except http://krb.cryptonotepool.com/. Last time he said he forgot to change at previous difficulty fall. And again today pool was mining at Hash Rate 738.23 KH/sec and no payouts... it was admin himself? OK then. This demonstrates that such things need to be forced on protocol level, changing something on pools won't work. There always be someone greedy who will mine this way despite afterwards this will cause network delays.

Since this does not work you can change it back to 10000. At least tax those miners.