Just in case anyone is tearing their hair out with the same issue... I was unable to even see the SSID of our WLAN at work. Turned off WPA but still no joy. Then I noticed that the access point had chosen channel 13. Thinking back to my tech support days I remembered that there are only 11 wireless channels mentioned in the 802.11g standard. Switched down to channel 8, restarted the access point and suddenly my G1 can see it and connect! Simple really, perhaps even not worth mentioning but hopefully it will help someone.