Thanks for the quick reply.
More details... The light on the card blinks when it is inserted, but not after that. In the Network setting panel, I choose 'wireless LAN card' in the list, then click the 'add' button. This brings up another panel labeled 'Wireless LAN - TCP/IP' and a configuration for 'non-spec ESS-ID: any'. There don't appear to be more options, so I have to dismiss this panel by clicking the 'ok' button. This goes back to the Network setting panel, and although there is now a new "Wireless LAN - TCP/IP' service listed, the 'connect' button is not enabled. Another panel says the wireless LAN service is offline.
During this configuration, the light on the card is not blinking.
Thanks.