Here is whats required for the outpost firewall to work properly with Windows 7. Hope this helps.
UPnP should work fine through the current and new version of Outpost as long as:
1. TCP Port 5000 (UPnP) is allowed for svchost.exe (XP, may be another executable on 2000, 98, etc.)
2. UDP Port 1900 (SSDP) is allowed for svchost.exe (XP, may be another executable on 2000, 98, etc.)
3. You have opened the necessary ports in Outpost itself to allow the necessary traffic for voice and video. These functions generally require a wide port range.
Following steps one and two should allow Windows the ability to perform the necessary UPnP negotiation to setup the NAT router to allow the Messenger traffic. And following step three should ensure no interference with the operations of your instant messaging client from Outpost.
That is my opinion and knowing your current situation, I really hope it works for you because I highly doubt that the next version of Outpost will allow an application to configure it's rules through the use of UPnP. UPnP configuration is generally applied to hardware devices like NAT routers anyway, so the three steps above really should work for you.
Again, that is my opinion, let's see what the developers have to say.
Source> Will version 2 be UPnP aware [Archive] - Outpost Users Support Forum