I added a PCIe 10GbE NIC card to a Dell 1950, which is my Networker server.  Previously I was using the 1GbE motherboard NIC.  Note I'm not trying to use multiple NIC's- just switch from a single 1GbE to a single 10GbE connection.

Hostid did not change and I am still in 100% conformance with clients and autochangers.  However the base license for Network Edition is now unauthorized (see below).  The symptom is when I start a backup it gets to 14% but doesn't load any tapes or write them.  So I'm thinking that the Base License depends on more than just the hostid (as opposed to the Clients and Autochangers which are still conforming).