Hi Len,
R40 and other Thinkpads with built in wireless has something like a list of 'allowed' wireless cards in the BIOS. AFAIK there is a hack that would change the BIOS and make it accept the other wireless cards. The best way is to buy the wireless card from IBM.
I am not so sure if I am allowed to discuss this here as per forum rules but try Google on the topic... (ex. R40 wireless bios).
More on the topic:
http://www.thinkwiki.org/wiki/Proble...I_network_card