Did you also reboot the test computers? Did you physically unplug (at least 10 minutes or more) all your network devices too? Not only the power cables, but also the LAN cables too where applicable.
Did you format the jffs partition and do at least three reboots (via the gui)?
If you did the above and it still doesn't work, it is safe to assume that firmware version you have installed isn't working. Does an older version work?
SOLUTION FOUND!
So, first off, to answer your questions, no, I did not reboot the test machines because this is something I'm changing settings on the router level as it interacts with the WAN, so individual test PC's
should have no affect on the outcome.
I did unplug my modem the entire time I was working on my router (more than 10 minutes), but I did not unplug the LAN cables as you suggested. As I stated before, the router was rebooted at least 3 times (probably closer to 5) via the GUI as I'm a bit OCD and wanted this problem solved.
Also, I have no clue how to format the jffs partition - googling seemed to indicate it was something for custom firmware like ddwrt or tomato. If formatting the jffs partition is something applicable to stock firmware, I have no idea how to do it.
So onto the solution; it took me walking away and eating dinner with my family and taking a break from this issue to get a different perspective on the issue. I had been using a number of online sites to test if my port forwarding was working (could have sworn this is how I tested it successfully in the past too), sites like
http://canyouseeme.org/ and
http://www.yougetsignal.com/tools/open-ports/ and several others I found on google. All the sites reported the ports being closed.
In my router I went to System Log - Port Forwarding and could see my ports were being reported as being forwarded there, yet the sites were saying I had no active forward.....then I found this -
http://www.pcwintech.com/common-problems-fixes-port-forwarding. Taken directly from that site:
"Most online port testers fail no matter what if nothing accepts their connection attempt. This port tester program will open the port on the system it is running on and listen for a connection from this site. So when the port tester program says the ports are open you can count that they are 
"
The poster then links to an app he made (that also has a portable version on the major geeks download page if you are like me and don't like installing throwaway/one use apps) and low and behold my ports were forwarded properly the entire time...I even tested by turning off random ports and testing again to ensure the program wasn't bs'ing me.
So it would seem to me in this newest firmware,
if you could test for forwarded ports before with online sites, you no longer can. Use the program I listed and you should get a reliable answer if you find yourself with this issue running on ASUS firmware 3.0.0.4.380.7266.
I should mention the only time I forward ports is when I host online sessions for netplays of classic video games from the snes-gamecube era via emulators. I hadn't hosted such a game in about a year but low and behold a buddy of mine and I are gonna play later this week; so when I went to fwd the port, that is how I got into this mess. I will update in a few days as to the success of my ports being forwarded properly, but as of now that program gives me a much larger degree of certainty that the ports are forwarded and it's the modems firmware preventing online tests from working properly, but an app that tests for open ports will work fine.
Hope this helps OP and others on this thread! Thank you L&LD for your time! So I probably jumped firmware's and needlessly went through tons of router settings for nothing...but alas at least I am a little more network savvy now and re-adjusted all my router options so I am familiar with them again, lol.
