Boot Problem with Wireless 1450

I have a problem with my Dell Latitude D505 and the Wireless 1450 802.11a/b/g Wlan Card

When booting and after the Desktop shows it takes about 3-4 minutes before the NIC and the dell wireless program shows up
also in that time i cant access the system

But when i disable "Client for Microsoft Networks" it boots fine and connects in 4-5 secs and i can surf fine but cant connect to the network computers
does anyone have an idea for how i can fix it?