problem connection from external ip on port 80

[million46]

Hi,
I have a problem with xampp on windows 7 ultimate.
I tried to listen to port 80 and 8080, the result is that the port 8080 I can also be accessed from external ip, and port 80 can not access.
Instead the internal LAN, I access from both ports.
I do not have direct management of the router, but my ISP says that you have configured portforwarding.
I also tried disabling windows firewall.
Does anyone have any ideas?
thanks