Dont know if you have solved this, but from memory, TCP & UDP ports to be set on the router under applications and gaming and the ip addy given to your pc by the router needs to be added, and you change from passive to active or is it active to passive in DC++ and add the port numbers you have allowcated on the router.
The above advice may be right, but due to needing a memory upgrade I could have forgotten just how to do it.
Also some hubs dont allow some types of search, cant remember whether its through active or passive though, dont use DC++ anymore usenet is my friend