Are you using a router?
If so, D3 and D2 do not behave the same way.
D3 can use UPnP to connect through the router,
but D2 cannot and in fact UPnP will screw up
any manual port forwarding you have done for
the D2.
See my post here:
OP D2 Router/WinXP Help Needed: Firewall Error Do you really have an IPv6 address?
RFC2374:
ftp://ftp.ipv6.org/pub/rfc/rfc2374.txt(it seems ftp links are not allowed in the UBB URL tag...)
If so, you may be SOL. But you're likely on the fastest networks
in the world! Maybe you are looking at the MAC (machine
addressable code) address?
Are you using a proxy server? If so - kill it.
(If your ISP will let you...)
After, have a look at my website (below), Does it
report an IPv4 address?
Have you asked your ISP if they are filtering any ports
and if so which ones?
In general I find Norton destabilises windows installations
so that their behaviour can no longer be predicted.
You are now running Norton-Windows not MS-Windows.
Have you been able to connect to the D2 in the past?
When did it stop?
What happens If you re-install windows (without norton)?
Have you ever installed an "Internet Accelerator" program?
If so, uninstall and re-install the tcp/ip stack, or windows itself.
Are you using a USB modem and access manager?
If so, ask for the ethernet modem and upgrade to XP
and do not install the ISP's access manager.
Don't take any drastic action on my suggestion alone though,
these are just some thoughts.