UPDATE regarding ASICs
If you were experiencing around 30% reject rates when using ASICs (scrypt and SHA256), this might be fixed now. We permit ntime rolling into the future for 1000 seconds (default slushs implementation of stratum, some pool implementations allow even higher ntime future rolling).
If you are hash buyer using own pool and if you have issues regarding blocks (generating not valid blocks), please let us know that ASAP - in such case, we will have to revert this fix.
BRILLIANT!!! Just switched my Terraminer IV over to Nicehash again and NO REJECTS (last week was getting up to 80% rejects!) Only been running a few minutes though, so we'll see if this stays stable... but thanks for sorting this out....