IPSEC issue with Lenovo T60 and Verizon UMW190 USB EVDO aircard

When using a Verizon wireless UMW 190 EVDO aircard on a Lenovo T60 laptop running Windows XP Pro, I discovered that if I turned off the on-board WIFI chipset using the front selector switch... I found that IPsec tunneling would no longer function (no DNS resolution through IPsec even though the tunnel connected properly). Without IPsec running, IP and internet access worked fine. When I switched the on-board WI-FI chipset back on... the IPsec DNS resolution worked correctly after that.