The network connections should load and connect to their default settings
even before you log on. So if you were to boot up and let the computer sit
at the log-in screen, it would still connect to the network (or default
wireless network , if there is one). But like you said there can be a delay.
It takes about the same amount of time to load the network services whether
you sit idle or log on. You're just logging in before all the services are
loaded.
In past versions of Windows, you couldn't log on until the services were all
loaded. This meant that at the log on screen, you'd see the "Windows is
starting up" or "Starting Services..." message for a while before you could
log in, or even after typing your password, you'd sit and wait with the
scrolling little line thing on that dialog.
In XP, you're allowed to log on, while the services keep opening in the
background. MS believes this helps you feel more productive, because you get
to your desktop faster. It's more psychological than anything, but it makes
you feel like the OS is faster because you see your desktop sooner. But like
you said, there can be a delay before all the services are ready for use.
So, long story short... "this behavior is by design."
______________________
Shawn