Aside from the forum location, I think you have 1 of two possibilities:
1 - You are behind a router, or have a firewall running somewhere between the aMule machine and the internet. Check all ports, check firewall rules, check router port forwarding using the hints on the Wiki pages and see if you can spot anything wrong.
2 - Your ISP kills off p2p traffic under the header "traffic shaping" or "quality of service". In that case the only action you can take is to end your subscription and move over to an ISP that does not do this.
And one notion: With this little information in a post, it's very hard to say anything sensible about it
