My wife's iMac has recently started displaying fuzzy, wavy lines across it - like static on a television set. She has a 15" iMac 1GHz model. Everything else seems to work - and icons and applications are visible, they're just behind this fuzzy static. She is using the speakers that came with the iMac and we've never had problems with those before. Anyone have any ideas on what could be causing this or what to do? If it continues we'll just have to bring it in to the local Apple Store.