I've got a home wireless LAN made up of two pc's: the one connected to the internet is a desktop win98 with flat ADSL. Avast works and updates as soon as I'm connected to the Internet. This PC is behind Sygate firewall. Internet connection sharing is running on it. It has dynamic IP to the outside and fixed IP on the inside.
The second is a notebook with XP, without firewall, and connects to the internet through the desktop ICS and gets its own IP trough DHCP. TCP/IP, HTTP, FTP, SMTP, POP and all other services are running smoothly. Everything's up and running.
I installed Avast 4.1 also on the notebook.
What happens is that the notebook tries to connect and to establish a connection to virus database and a window appear:
"Downloading file servers.def.stamp", progress bar shows 100% and it stays still there. After few minutes, the red warning "unable to download...." appears in the right bottom corner of the desktop.
Clearly, I tried opening all access incoming and outgoing on the firewall for my table (192.168.0.x) for all protocols and all ports to no avail.