If you have the network settings set for Automatic, the PB will attempt to find any network access, Ethernet, wireless, modem. It is possible that the airport card could kinda see the network at work but could not access it. If you check the IP addresses you will probably find that they are similar. Having said that, the PB should have been able to access your home network without any problems what so ever. Unless you are setting your own IP address and NOT allowing DHCP to work.
Check the DHCP settings to see if you have the machine set to get its IP address from the Wireless base stations.
Hope this points you towards an answer
i recently got the airport extreme card for my g4 ibook. i set up the ibook to connect our home network wirelessly and locked the setting so they would stay the same and not change about. i got to work last night and turned on my ibook and the network settings had unlocked themselves and changed to a completely different ip address which does not work on my home network.
did the settings change themselves because the ibook couldn't find a wireless network at work? surely it shouldn't have unlocked itself?
does anyone know why it could be doing this?
many thanks in advance