The best thing for the DI-Link 604 is port forwarding; see both of these instructions because I'm not sure which version you have:
http://www.portforward.com/english/r...2/Limewire.htm http://www.portforward.com/english/r...4/Limewire.htm
Need to set a static ip 1st.
After doing this let us know if you can connect.
When you said your computer is connected directly to the net, what do you mean? Are you using an internal dial up modem or something?
For software firewalls, you need to configure them. And only use one, not two. 2 will actually give you less security. I don't know about configuring about your particular ones.
Firewall configuration instructions (click on link) I've heard of some people having problems with pc-cillan.