Sorry, my DSL had been down for the last 2 days.

@jpollar
So you are connecting to this board using a proxy on the firewall. And privileged ports as 135, 139, 445 are opened for incoming connections to you? Sounds weired to me. You're sure you aren't using a proxy in general? See, there is a technique called 'transparent proxy'.

Anyway, if you ask, you probably can find a guy who is willing to change his portnumber to 8080, but what have you won? You can connect to that host and do some filesearch, but to download a file you must do a direct connection to the filesharing host, who is probably running at standard port.
The only solution I can see here is to find several people to run a private net on port 8080 (find a client who enables you to change the CONNECT_STRING). Those, who are able to connect with full portrange, may have a second client running on gnutella-net.

Btw.: trying a portscan through a firewall usually should ring all the alarmclocks there. Don't be surprised to have a nice talk with your boss. Using telnet to test the connection to a server:port should be the better way, though usually all blocked packets are logged, so don't do even that to often.