I got it to work.
I tried to space out the router entries and go through the process again, but that still didn't work.
I thought I would uninstall the software and then reinstall it. I saw that there was a new version of the program available, so I decided to install that one instead. (2.0 I think it is)
After 2 and a half years, Linksys WRT160N is STILL not on the list!!! what's the deal with that???
Anyway, this software did as much as it could. It estimated what the address would be, but still could not port forward.
So, I changed the address on the router from 237 to 254 ( which is what it estimated it would be), went through the manual process again and it worked!!!