Antivirus setup problem

I get following message when I am logged on my WinXP:

Other HTTP error(0) while trying 216.127.72.135:80//iavs4x/servers.def.

What is the that?

worksforme, check your proxy/firewall settings please.

That can’t be the problem. I’m now on a win98 computer that’s not in the same network. And this computer have the same problem. Everything has worked fine until this week. The problem is when avast should do the update. Or is trying to update.

On a different computer with WIN XP that is’t on the same network, have the same problem.

In these ‘different’ computers (or ‘another network’), is there any firewall or proxy filter installed?