MP 790 wireless

I have reciently aquired an NEC 790 wint a Proxim/Orianco wireless card. I have a MS MN-500 base station with WEP set at 64 bit. I also have a D-link firewall/router attached to my cable modem. I seem to be connected to the network. My router sees the 790's ip as an attached device. Unfortunately I am unable to access anything on the internet. This would be OK. My real goal is to run applications on my winXP pro desktop. Any ideas or suggestions. I really need the small footprint that the 790 provides.

install vxutil (free app), and look at the info in it, if it gives an IP address different from 192.168.xx.xx (for example 169.254.xx.xx), that's the problem! renew the ip (by reinserting the card).
other suggestions: try to enter the wep key as hexadecimals, check the ip/dns/gateway setup if you don't have DHCP, and last but not least, search on this forum!