If you have a look through the other posts you might find answer to your problem, you could try the suggestions in this
thread or just try this first
Open up SFC3.ini in the root of the sfc3 directory, notepad is fine.
Scroll down till you find [meta]
insert a new line underneath and type in "IpAddress=xxx.xxx.xxx.xxx" where xxx is your external IP.
It should look something like this,
[Meta]
IPAddress=xxx.xxx.xxx.xxx
Name=me@myisp.com
Password=*****
MapName=Map4.mvm
TestPatchUtility=1
EmpireMapView=1
Nickname=jollybengal
See if that works, this fixed all my problems getting in to D3, and stopped me