First of all, checkout @helper.select, as it can probably help you here, eg:
@helper.select(form("networkInterfaces"), networkInterfaces.map(i =>
(i.Name -> i.DisplayName))
Now to solving your problem:
1) Have you checked what gets rendered? Is what you are expecting in the
2) Have you checked what is going over the wire using browser developer
tools (eg, firebug, or the chrome developer console)?