I just want to say that i read this entire Thread, and i had the usual problem with the fact that i am behind a router.
I tried everything PORT Forwarding, checking firewall settings etc etc. IT SHOULD work, i thought.
I then clicked the MISC section of my router and found that DMZ was on and was directed towards my PC LAN IP ADDRES.
I turned it off, and bingo it works.
So my DCC send works because i have
Routed my DCC port range to my PC
Routed my PC as server from my router
Setup my firewall(software) to allow the port range to be passed to my PC.
And finally Turned off DMZ, that was causing me troubles.
I just had DMZ on sinze i have a software Firewall too, and i also play some games on the net with this PC.
I case you wonder what DMZ is, here is a short description.
DMZ Host DMZ (DeMilitarized Zone) Host is a host without the protection of firewall. It allows a computer to be exposed to unrestricted 2-way communication for Internet games, Video conferencing, Internet telephony and other special applications.