I have a 3com Superstack 3 switch 4200 installed on a few of my networks. When I have devices plugged into the switch the activity lights on the ports flash constantly, even though I know for a fact the computers hooked up to the switch aren't sending data. They typically flash in sync with one another or sometimes half will flash then the other half will off and on. Does anyone know what might be causing this or if there is a way to make this stop. I know 100% I am using the right cable types and I know for a fact that the computers connected to the switch are not sending data 24/7 as the lights show. Any help would be great. Thanks.