My ThinkPad T60 is configured to connect to my cell carrier via its internal Sierra Wireless 1x EVDO adapter controlled by the Windows XP Network Connections. The remaining networking connections are controlled by the Thinkpad Access Connections utility. This arrangement worked stably for over a year. When I now attempt to use the WAN connection, I receive three Error 711 messages; the first two state "Cannot delete saved password" and the third "Cannot connect the phonebook entry". The same error is reported with the WAN card switched on and off. Device Manager indicates that the WAN card is working correctly.
The Remote Access Connection service is running normally.
I have run sfc and checked for spyware. Running system restore fixes the problem but it returns shortly.
Any suggestions as to how I might proceed would be very much appreciated.