warning: call_user_func_array() [function.call-user-func-array]

With alpha4, when I visit the module's config page (../admin/build/icons), I get the following error:

warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, 'icon_settings_form' was given in /var/www/[mySite]/includes/form.inc on line 372.

This doesn't happen when I revert back to the 07/07/2008 dev version. But then again, the dev version displays only a 'TODO...' text there and has no config options.

I don't see anyone else reporting this issue. Could it be a conflict with another module perhaps?