I have a WRT54G v4.0 and it seems I need to keep the router far away from an RCA (Comcast) cable modem to keep it from dropping connection. If it is too close, the cable modem will constantly reconnect (seen by LEDs sequence). The WAN connection will be affected too. If I disable the wireless, the WAN is rock solid. Is this common? I mean don't people usually put their cable modem and router together?