Moved this to Personal Firewall for better attention.
I'm sure it's just a question of opening the right ports (they'll still be stealthed).
Is this any help: http://forums.ubi.com/showthread.php/260116-Ports-For-HAWX-Forums ?
Open SecurityCenter by double-clicking the taskbar icon
Click Web and Email Protection
Click Firewall
Click Ports and System Services
Make adjustments there
Also if you have game hosting software make sure it has full permission under the Firewall > Internet Connections for Programs section
(Hint: make it easy there by clicking Program at the top of ths list to rearrange them alphabetically).
Or you could contact Technical Support, it's free via phone or online chat. Linked under 'Useful Links' at the top of this page.