You need really low latency to get the most reliable play out of NIN as it is far more dependent on latency than any other class. If you have any jitter in your connection, or even high ping/lost packets you're going to encounter a lot of mudra issues. Chances are it's not you or the server, just a distance/routing problem leading to higher latency. The servers are in Cali so unless you're near the West Coast you're ping isn't going to be all that great.