at the start of last week my DSL broadband started to disconnect everytime i download from bitlord 1.1
avast does not connect and does not disconnect. It's just an antivirus.
Maybe you're seeing the WebShield alert that there is a virus and the
connection with that specific website will be closed: the internet traffic (HTTP) is disconnected, not your DSL connection itself.
Better will be having more details about that... Are you receiving error messages? Can you post a screenshot?