Add Local Avatar have a bug.
http://wordpress.org/extend/plugins/add-local-avatar/
In file avatars.php there is a bug. When you first activate resize, the resize upload size is disabled, then the scale value can be NULL. In the avatars.php file the line 659:
$resized_file = image_resize($root . $path . $file, $avatar_options['scale'], $avatar_options['scale'], true, SUFFIX);
should be replaced with:
if (is_numeric($avatar_options['scale'])) {
$resized_file = image_resize($root . $path . $file, $avatar_options['scale'], $avatar_options['scale'], true, SUFFIX);
}
else {
$resized_file = image_resize($root . $path . $file, $avatar_options['size'], $avatar_options['size'], true, SUFFIX);
}
Best Regards