kamykaze, as milos said, the avast program's "webshield" acts as a proxy.. with "webshield" enabled, all internet-connections are routed through "webshield".. if you disable "webshield", any internet-connections that you had, which were routed through "webshield", are lost..
so, if you want to temporarily disable "webshield", you need to disable it before making any internet-connections.. with webshield disabled, the internet-connections will not be routed through "webshield"..