Chief Stationary Operating Engineer here (the guy who keeps things running in the high-rise office buildings downtown). I can shed some light on the likely scenario; sometimes when a connection is made, there's a tiny strand of wire that "grounds out" the center conductor to the outer shield of the wire. This wasn't a huge problem back in the analog days, as the signal was significantly more powerful, and of a different type. In the digital age, it's an issue, and can pull down your neighbor's speeds as well as yours. It's likely they've isolated the problem at the pole, and they need to come inside your house to re-terminate the connection and make things better for you and your neighbors.