alf--FWIW, giving each machine at home a static local IP solved most of my networking problems. You have DHCP turned off, so I'm guessing you gave each machine a static IP, like 192.168.1.2, 3, 4, etc. right?

If so, then each machine needs to be mapped to a port in the router's port forwarding section, and the LW prefs need to be set to manual with the appropriate port.

Oh--too many incomplete files trying to connect on startup can also trigger a lockup at times.