Yes, there is a Thwack thread about this issue. It is located here:
You might be seeing the new NetBIOS resolution that we are doing in NTA 3.1. As you see in the other post, at the present, you can't turn off the NetBIOS from within NetFlow. We'll correct this in a future service pack hopefully, but you can turn all name resolution off if you want. But there is a workaround... You can open up your network cards "Properties". Select the TCP/IP protocol, open its properties, hit the "Advanced" button, click the "WINS" tab and there in the "NetBIOS Settings" grouping, click the "Disable NetBIOS over TCP/IP".
If it is truly the DNS resolution that you want turned off. It can be done in NTA 3.1, but you'll need to have Tech Support walk you through how to do it.
Hope this helps,
yeah, unfortunately this is DNS traffic, as the destination packets to the DNS server are UDP 53. I'll have to open a case then.