Duplicated shares on NBminer

Hi there.
For over a month everything was going fine with NBminer, on herominers pool, when suddenly i started getting duplicated shares. Now the rig says that i don’t have many but it is because i restarted it so you know the miner erases all the previous data.
do you have the same problem? Do you know how to fix it?
yes i already restarted many times, i downloaded the latest version of NBminer and deleted the old one.