This is driving me nuts, since upgrading to Leopard my wireless connection which ran perfectly in Tiger is going mad, The signal strength is up and down like a yo-yo, my IMac will not reconnect after reboot or sleep, its timeout after timeout. Done the keychain update, reconfigured my network prefs, no joy and my wifes Macbook is working fine 10 feet away. Aargh!http://images.macrumors.com/vb/images/smilies/mad.gif