Apparently it's not 10.4.9 but the new Airport Update...
http://discussions.apple.com/thread.jspa?threadID=883021&tstart=0
one solution:
http://www.macfixit.com/article.php?story=20070202133651898
http://discussions.apple.com/thread.jspa?threadID=883021&tstart=0
one solution:
http://www.macfixit.com/article.php?story=20070202133651898