It was amazing that Scott found it so fast. I was on the Windows side of things. Inside Windows they were using the iSCSI initiator to connect to the FreeNAS. All the sudden Windows would just log a ton of iSCSI events and go down.
I looked up the events and most people resolved them by putting the iSCSI traffic on a separate NIC. This happened two days in a row at about the same time each day. I was looking at snapshot, backup, etc times when Scott found it in the FreeNAS logs.