add WEP and renew IP address

hi forum,

I am participated in a project, part of this project will search the Wi-Fi
network and try to connect one of them. I found I am almost at the end of
the project, except this problem: after adding WEP, the PPC can not have
correct IP address (only 169.254.xx.xx).

When I disable WEP, everything is fine. When using WEP, it seems the
connection is fine, except the IP address. I searched the forum, seems it
has something to do with OID_802_3_MULTICAST_LIST. But how to set it? use
DeviceIoControl as I set SSID, or other function? Anybody has similar
experience?

thanks,

Eric