Wireless connectivity after sp2 install.

I have tried everything other than uninstalling sp2 to get
my wireless internet connection up and running again. I
have updated all the latest drivers and firmware for both
my router and wireless card. In the event log i have a
number of the following two error messages:
1."Your computer was not able to renew its address from
the network (from the DHCP Server) for the Network Card
with network address xxxxxxxxxxxx. The following error
occurred: The semaphore timeout period has expired. . Your
computer will continue to try and obtain an address on its
own from the network address (DHCP) server."
2."The IP address lease 192.168.1.100 for the Network Card
with network address xxxxxxxxxxxx has been denied by the
DHCP server 192.168.0.1 (The DHCP Server sent a DHCPNACK
message)."
PLEASE HELP!!!