At a guess I would say its the router Andersp, although have you installed ANY new software on the machines lately? Or was the Cable modem drivers updated or anything?
(hide) In the mood for a quick game that is guaranteed to finish within 2 hours? Create a new game of your preference, select the Time for game and set Time to 0 days / 1 hour, Bonus to 0 days / 0 hours and Limit to 0 days / 1 hours. (TeamBundy) (show all tips)