Had a nasty case of the vanishing AOLs here in June-July, mostly at weekends and in the evenings. Since AOL is still my ISP - don't ask! - this meant I lost my internet connection for up to 75 minutes, then it was back again with no hint of aolpology. Note to self: stiffen the sinews & speak to those people at zen again!
Did you ever think there was maintaince being carried out and giving them a call to check that before moaning. The majority of DSL problems in the UK are not the cause of the ISP but down to user themselves