Had the same problem with Tiscali/Talk Talk for months... broadband would be fine for an hour, then drop off for an hour, fine for a day, drop off for a day. Went on for too long. I rang a couple of weeks back and said I was totally naffed off with the service. They said they'd get an engineer to check the line and get back to me. Haven't heard a thing from anyone, but since then, the line's not dropped off once, and what was regularly a 250kb or less download speed is now regularly at about 6mb. Bingo! I think they can boost the juice to the broadband if you complain enough.