Connection problems to IP subnet

I'm having some very selective connection problems. Most of the big areas, especially those for the wintersday celebrations are hosted on servers in the 206.127.147.* subnet. I can play perfectly well, as long as I am on these servers.

HOWEVER, as soon as I go to a region/town hosted on the 206.127.146.* subnet, the client downloads a bit of data, and then hangs on the "Connecting" stage.

Things I have tried:
Different IP, different ISP
Downloading and reinstalling the GW client
Repairing the GW install using my install DVD.
Virus scan, spybot and adaware scan.
Defragged the GW.dat file.
Add the subnet to the trusted zone of my firewall
Disable firewall

None of which worked. I am desperate to play as I only have today and tomorrow to do the wintersday stuff, because I'm going away.

Gw has always worked perfectly well, I didn't play for a number of weeks but logged in a few days ago to try out the wintersday celebrations, which is when I started getting problems.

Any help would be appreciated.

Thanks.

*sigh* Guess no-one has a clue then.

Oh, its not working for 206.127.145.* either.

Just now I tried to load Kamadan, usually hosted on the 206.127.147.* subnet (and it usually works), but at that time the server hosting was on the 206.127.146.* subnet, and I couldn't connect.

So it is definitely a problem with the different subnets.

No response from the ticket on plaync either. Oh well. Bye bye wintersday.