Weird Vista network startup problem

Asus A8N SLI with all nvidea chipset (I know) as well as
nvidea network card and nvidia 7600GS video card
(single). I connect to the Internet via a Linksys
Wireless Router by a wired connection (but it doesn't
matter if I use a linksys wirelss card instead of the
nvidea ethernet) If I start Vista by clicking on the
login screen as soon as it appears the network will not
load (Taskbar icon is red and never turns blue). If I
wait >5 minutes to login the network often, but not
always, the taskbar network icon is red. However if I
wait just 2 minutes (after the logon screen appears and
until my hard drive stops churning, then login then the
taskbar network icon is blue (avaialble).

Once connected I never have another network problem and
download speeds are fine. I've searched in the Event
Logs and used bootlog, but cannot sort this out.

1-Does anyone know why this would happen?

2-Without rebooting is there anyway to get the network
drivers to try to connect again? I've tried to
deactivate and activate in Device Manager, but it does
not work and I have to reboot.

Thanks