Ok I see so one way you have the PS3 directly connected to the modem and you can see more people.
When you hook up the router to the modem and PS3 to modem then you have the issue.
When you hook up the router and do the test on PS3 what nat do you get? Sounds like its a firewall issue.
You probably need to follow these directions find, your router the chose PSN.
https://portforward.com/routers.htm
Or just get a 360
It don't matter i bought a more powerful router, that was the problem all works fine now. (for both PS3 and Wii online) ty for the help guys.
BTW i would never own a 360!
Flame on!