My firewall allows limewire sharing from internet and that stuff, I checked it.

We dont have the same listening ports...
But we have the same manuel forward ports.

And the linksys modell is : Linksys Wireless G 2,4 GHz, Modell : WRT54G

Anyone who knows what the problem is?

You need to forward your listening port. Whatever your listening port is in LW's
options...that's the number you need to use when setting up port forwarding. Check out the link below for more info.
Port Forwarding for the Linksys WRT54G

You'll also need to make sure that you've set up a static IP address first. That link above will give you further links to static IP setup