Linksys WAG54g wireless connectivity problems

Hi,
I've been using a Linksys WAG54G wireless modem/router for several months however recently it has stopped being able to connect to the router wirelessly when I switch on the computer. The computer registers the signal strength as excellent but cannot aquire network address and thus has the error signal 'Limited or no connectivity'. When I click on the repair function it cannot renew the IP address and therefore stalls. This does not happen all the time however it is occurring more and more often. My system specs are:

Dell Inspiron 6000
Intel® Pro/Wireless 2100 (802.11b)
XP home spv2.0
Firefox
Zonealarm
AVG

Thanks

 

check your encryption. update firmware and drivers.