Problem with Real Weather and LAN connection

I like flying with the real weather setting. After installing FS9 on a new computer I have this annoying problem that the connection with the weather server works well for about 10-20 minutes, but then the LAN connection and with that my internet-connection is closed down and all the supporting programs I've got running on WIDEFS and a laptop crash or stop.;( What could be the problem? I'v had the same arrangement (PC connected to a hub, laptop connected to the same hub, hub connected to a router, router connected to broadband modem) with another PC running for months without trouble.Help appreciated!