Port Forwarding - Please Help

[notcarbonated]

Hello everyone,
I've been using Transmission to download and seed torrents for years and now all of a sudden I can't seed anything (downloads work just fine). I checked the preferences and it says that my Peer Listening Port is Closed. After doing some research, most sites are telling me that I need to forward the ports for transmissions on my router but I've had no luck with it.

Some introductory information:

ISP: At&t U-verse Broadband
Router: 2 Wire 3800HGV-B (modem + wireless gateway)
System: Macbook Pro, OS 10.6.4 (networked wirelessly)

Here's what I've tried:

-My Mac firewall is, and has been, shut off.
-Transmission is, and has been, set to Automatically Map Port, enabling NAT-PMP.
-Typing the port shown in my Transmission preferences into CanYouSeeMe.org results in this Error:

Error: I could not see your service on 99.66.147.144 on port (52033)
Reason: Connection timed out

-Going to PortForward.com for instructions on my router doesn't give specific instructions on enabling port forwarding with Transmission. I followed the default guide and created an exception in my modem/router's firewall for the "user defined application" I called "Trans" which covers the ports between 49152 and 65535 on both TCP and UDP protocols. Still, when I choose a port in Transmissions within that range it still comes up closed and I can't seed any of my torrents

-In case it helps, here is my Debug Message Log when I filter "forwarding":

2010-10-18 21:48:01 -0700 natpmp.c:70 [Info] Port Forwarding (NAT-PMP): initnatpmp succeeded (0)
2010-10-18 21:48:01 -0700 natpmp.c:70 [Info] Port Forwarding (NAT-PMP): sendpublicaddressrequest succeeded (2)
2010-10-18 21:48:01 -0700 upnp.c:105 [Debug] Port Forwarding (UPnP): upnpDiscover failed (errno 2 - No such file or directory)
2010-10-18 21:48:01 -0700 upnp.c:125 [Debug] Port Forwarding (UPnP): UPNP_GetValidIGD failed (errno 0 - Unknown error: 0)
2010-10-18 21:48:01 -0700 upnp.c:128 [Debug] Port Forwarding (UPnP): If your router supports UPnP, please make sure UPnP is enabled!
2010-10-18 21:48:01 -0700 port-forwarding.c:95 [Info] Port Forwarding: State changed from "Not forwarded" to "Starting"
2010-10-18 21:48:09 -0700 natpmp.c:75 [Debug] Port Forwarding (NAT-PMP): readnatpmpresponseorretry failed. natpmp returned -7 (the gateway does not support nat-pmp); errno is 61 (Connection refused)
2010-10-18 21:48:09 -0700 port-forwarding.c:95 [Info] Port Forwarding: State changed from "Starting" to "???"

I've been trying to resolve this for over a week and I have no idea what else I can try. I would be eternally grateful if you guys could offer me some advice or tell me where I might look.

[papibe]

I don't if this is going to help, but I have a similar modem: 2Wire 2701HG-B.

First of all, in my understanding you just need to set 1 port (I believe yours is 52033, mine's 51413 in Ubuntu server). Set the range from 52033 to 52033, and that will suffice. Then your firewall has to be set to: "Allow individual application(s)". The final step is to connect the "Trans" to your machine by selecting its network name and then adding "Trans" so it will appear on the right column. Finally press done.

I'm sorry if that was too obvious, but you never know.

The only case that I've seen this is when I've forgot about it and tried to run Transmission in another machine. When that happened, all incoming traffic was being divert to the original machine (the one that had the rule on the router). I solved this just changing the port to a different one (in the new machine) and creating another rule (Trans2 -> 51414 -> new machine).

I hope it helps.

[notcarbonated]

Thanks papibe! Your instructions were fantastic. The problem was that in the instructions i found on Portforward.com they did not show that i need to set the same port at both ends of the range when creating a profile. Now it's open and everything fine

Once again, thank you for taking the time to help!