Lost network connections with Vista

Every time I reboot or shut down and restart my computer Vista loses the
network connection. Diagnose and repair reports back the IP and DNS needs to
be re-established. When I tell it to obtain the addresses it creates a
“second� network connection, which it then tells me I need to disable.
Disabling one disables both so the next step is re-enabling the card. After
re-enabling the card Vista refreshes the settings again, once more creating a
“second� network connection that needs to be disabled, starting the cycle
over again.
After repeating this process several times a single network connection will
final be established and everything works great until I need to shut down or
reboot and the process starts all over.

Any ideas?

I’m running an HP system with an on-board nVida network controller connected
to a Linksys router.