Important Change

I tested both configurations with firmware 1.46.2, as seen in the second picture.
I switched over to firmware version 1.45.7 as suggested by NotANick (from here). This did not solve my NAT error problem.

One thing solved my other connection problems (like being disconnected in Counter-Strike).

This Is My Original Configuration

Hover cursor over image for picture #.

After reading this page, please look at the other configuration(s) I tried.
Configuration 2