"Could not find a suitable free port" as normal user
I'm trying to get DC++ working in Linux. (DC++ is a peer-to-peer file sharing thing.) I have installed linuxdcpp, and I can connect to a hub, but I do not get any search results. In Windows DC++ works just fine. And I use the same settings! These are: Firewall with manual port forwarding for the incoming connections (hub/UPnP override not allowed) and Direct connection for outgoing.
Now, when I start linuxdcpp as normal user from a terminal it says
However, when I run linuxdcpp as root, I do not get the "Could not find a suitable free port" error and I can search.
Loading: Hash database
Loading: Shared Files
Loading: Download Queue
StartSocket (tcp): Caught "Could not find a suitable free port"
StartSocket (udp): Caught "Could not find a suitable free port"
How do I get to use DC++ as normal user?