I am not really comfortable posting a screenie but I just configured a linksys and it took a bit of work.
I ended up putting everything in the "View port Range Forwardign" section of the menu. My router which is a Networkeverywhere NR041 (made by Linksys) had a tab at the bottm of the basic port forwarding page.
When I clicked the range tab I ws able to add everyting I needed. For single ports I just added 7777 to 7777 in the beginning and ending sections.
I did notice that I had to do this a couple of time b/c something kept changing the damn ports. I never was able to get the plain jane port forwarding to work. Only the ranges. Hope this helps. I will try to help as much as I can but this is blind leading the blind