|From the manual http://www.downloads.netgear.com/fi...|
You can connect to the wireless router by typing any one of these three URLs in
the address field of your browser, then clicking Enter:
When prompted, enter
admin for the router user name and password for the router password, both in lower case letters."
Perform the factory reset again and repeat the login attempt. If this does not work then I would suggest contact netgear. Is it possible the router has been flashed with third party firmware at any stage? If so I believe it is a common occurrence that the factory reset fails and you would need to seek guidance from the firmware publisher.
Goin' Fishin' (Some day)