DC++ problem and bandwidth

My current setup:

Wireless Clients 192.168.3.X
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MT Router 192.168.3.1 wan ip / 192.168.1.2 Lan IP
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DSL Router 192.168.1.1 -----------DC++ Server 192.168.1.5

I am having A LOT of problems with dc++.
I want wireless clients to connect to the dc server/hub on 192.168.1.5
They can all ping it and connect to the hub and chat. We have been toying around with dc client settings and most of the time we cant connect to each other to download/upload. Sometimes, seemingly randomly we can connect and one client can download from the other client.

But the average download speed is 30KB/s
The same two clients can ftp between each other at 700kb/s or more.
Why is dc++ so slow? what is limiting it? does anybody have any advice on setting up forwarding or any rules that dc requires?

Im very new to MT and routeros. thx.

ps. we have to use dc++ even though it sucks.