Cablemodem frequent connection loss

Cable modems work on a network/grid that connects to a T3 router running at 45 Megabits per second. Each area is a grid and this grid only has so many slots available. Depending on where you live, you could have a busy grid, or a not-so-busy one. My grid for example, was very busy; so I didnt get very good performance and I had the same problems as you. (ie.. when the slots in the grid are full, a cycle is required which should put you back with the active users. The problem lies with the cable companies' lack of upgrades to their equipment to meet the needs of the consumer. There isn't much you can do besides maybe write angry letters or switch to DSL which has slower speeds.

I had a similar problem to this with my cable connection. For me it turned out to be I was not getting a good signal to the cable modem. My internet would work for several days, but would just drop out every once in a while unexpectedly.

Do you have any splitters on the coax between the line into your house and the cable modem? If so, try to remove them(or at least all but 1 if you use your cable for TV as well) and see if you see any difference.