Orange (Wanadoo) has been having problems on and off for the past few months. Sometimes for short periods and sometimes for hours on end. The basic cause for this is the upgrading of exchanges to 8 meg BB. However last weekend a lot of isp's were experiencing downtime!
The longest I have been offline was approx 10 hours, average has been a few mins ~ 2 hours. Last weekend was the longest at 10 hours.