XP and wireless

I have one laptop with integrated wireless and ethernet
running XP professional and I also tried 2000
professional. My problem is when I switch from a
wireless to a wired connection or vice versa I am unable
to get the network browse list for up to 15 minutes.
Error message (unable to browse network or network is
unavailble). Can ping other servers and workstations and
even map drives to folders on the network. The PDC and
master browser is a nt4 server. When I look at the DHCP
manager the laptop shows 2 different IP addresses one for
the the wireless and the other for the nic. If I release
one of the leases and do a nbstat-rr and nbstat-r on the
dhcp server I am able to receive the browse list
instantly. Do not want to use static ip!