SMB keeps going unresponsive to clients

My CIFS sharing keeps going unresponsive to clients. I was using SMB3 but changed it to 2_24 in the hopes it will solve the problem. It still keeps doing this. I'm on FreeNAS-9.2.1.9-RELEASE-x64 and it was doing this in the 9.2.1.8 as well.

Any ideas of what to look for to diagnose this? Its driving me nutty..... Just a little nutty.