Firefox stops working whe I change networks

IF I am connected to a one network while using firefox and then disconnect from that network and connect to another on a different adapter firefox stops being able to find the internet, all new requeste timeout ("The connection has timed out"). If I start a new instance before closing all existing ones the new instance has the same problem. I need close all existing firefox windows and then start again.

Should i not be able to disconnect from a wired network and connect to a wirless and have firefox just keep working? Other programs I use just work it out with out being restarted.