When I installed 10.5 and had no problems with wireless internet. I've allowed updates up to 10.5.2, but made no other changes, and somewhere along the line (I think BEFORE the updates, actually) I started having trouble with airport. At first it would show a connection but then an error message (sorry, don't recall the details). Since the most recent update, I see a connection to my router (linksys) but I don't get any internet connection unless I plug into the router directly. Under airport in network preferences I get "not connected" and the message "AirPort does not have an IP address and cannot connect to the Internet" while under Ethernet I get "not connected" and "IP address unknown" even though I have an active, perfectly functioning Ethernet connection!

Actually, I just went to Network Preferences to check on the wording, and discovered that Ethernet says "Connected" and same for airport. So I unplugged the cable and sure enough, the airport is suddenly, finally working. WHAT? Hope it lasts!