Computer power supplies will induce noise on your lines, as well as other power supplies and could happen at anytime. Did you try unplugging these type of items? If you are looking in to a new system I would recommend UPB there is software to set these devices up and control them from a computer. UPB is real close in pricing to what X-10 used to be, and the product is more robust has a lot of nice options and work similar to X-10.