Troubles using avast Home edition with a VPN

I have just installed avast home edition. My OS is Windows 2000 Pro. I use a VPN to connect to my work. I can still establish a VPN connect with my work but when I use Outlook (not express) or IE these tools do not work. I cannot bring up interanl website (yes I use a proxy server) and outlook cannot connect to my mail server at work. Does anyone have any ideas??? Please help???

Brice, I can only figure out that it could be a proxy and/or firewall trouble.
I’m not sure but can you try to disable the firewall and see what you get?
About proxy, did you configure it into avast settings?

Can you ping your mail server?
Do you have a personal firewall installed?