Also,the time when is updated the servers were stressed and were damn slow...
Could explain, why some dialup users have/had problems lately...
Well there are hundreds of update servers to try and balance the load, in theory it shouldn't make much difference to a dial-up user as they aren't trying to digest the whole update in one bite as fast broadband connections try to do. I think it is possible more to do with resources also.
Many of those on dial-up also have under powered systems, so the system is going to get bogged down for reasons other than dial-up speed, like in the other topic - Chim's system Windows XP running on 256MB of RAN and a low powered processor. That lack of resources would also hamper the updates.