This is probably a daft question, but I'll ask it anyway. We have a dialup internet connection and ever since we plugged in our new PC we have had trouble with the phone. It rings twice and then cuts off. The display reads 'Ext tel in use' which is what we get when someone is online. Only, nobody is online or even thinking about it. Is there a setting somewhere which could be causing this? We think it must be to do with the PC because when I'm not in the office and the PC isn't switched on, we get messages on the answering machine which rings more than twice before the tape kicks in. XP Home and MacAfee AV and Firewall.