Some of the NV5000 cards have 3 sockets to plug the ribbon cables from the Ext. boards into and some have 4. If your board has 4 sockets you want to plug into the 2nd one, not the first.
As for the networking thing, have you clicked on the 'Network' button (it usually turns purple if it's clicked) to enable networking? If so are the proper ports forwarded through the router? Is there any software on the DVR computer that might be blocking the program from broadcasting?
Good luck, and let us know how things go.
Drew
Skyline Solutions