That's right, if the network only requires a regular wi-fi security password it can be added, but a username/password combination means you have a different layer of security to deal with.
jasonsc, as you've seen, it's not possible to provide that kind of information using the Eye-Fi card's standard method of adding a private network.
and if your network participates, you can hopefully connect the card to it using our Public Hotspots feature, which allows you to connect to Easy WiFi supported networks.
If this isn't an option, see if you can have the MAC address of the card approved by your IT department so you can skip the username/password authentication. To find the MAC: http://support.eye.fi/cards/how/how-do- ... c-address/
I hope this helps.