With firmware version 1.31, the Wireless settings page is blank when a browser other than Internet Explorer is used to access it - for instance, Firefox or Chrome.
All other pages appear and seem to work properly, only the Wireless settings page is empty.
Luckily, the Wizard still works and can be used to set the Wireless settings for general purpose use.
Older versions of the firmware worked fine with other browsers, including the Wireless settings page.