Vista - Network adapter "Lan connection" takes 90 seconds to start on Vista boot

Every time I start Vista I have to wait for approximately 90 seconds before the dial-up internet connection is established, because
obviously first the lan connection adapter has to be initialised before I can connect to my provider. E.g., the Event log shows that
Vista has started at 6:34:43 o'clock, and then only at 6:36:21 the network adapter "lan connection" is connected to the network
(that's from the event log). That's one and a half minutes!

I've disabled all sharing functions and set a permanent DNS address and gateway so I don't understand what Vista is doing there for
90 seconds. Is this somehow connected to network discovery? But there is absolutely nothing to discover!

Also, if I disconnect from the internet, the network panel in the control panel shows again that Vista is trying to discover some
non-existent network.

There are rumours that this behaviour is by design in Vista. In any case, on my WinXP system, the internet connection is established
PRIOR to loading the desktop, so I can start WinXP and immediately access the net. I want to do the same in Vista. I am tired of
waiting for 90 seconds sitting in front of my pc and waiting for Vista to establish the lan connection. What the hell is the system
doing during these 90 seconds?!!