BleepingComputer.com: Windows Vista And Wireless Networks

I work setting up communications equipment in remote camps. we use satellite internet connections and wirelees accerss points to deliver internet to the camps. I have come accross 4 laptops now in the last month that will not connect to an unsecured wireless network. all the laptops are vista machines and all the access points and engenius 3220. All the machines connect fine with a cable to the switch. any suggestions. Most of these cames are at least a 5 hour drive away so I need to get them any fixes by phone or try and fix it the next time I am in the area.