[Plugin: User Photo] Default image is not displayed for WPMU

I installer WordPress MU with multi site support (njsl-sites). The user-photo is not require to have an image for each user for each blog that is fine with me. However, if the image is missing the default image is not displayed. Any idea?

Here is a sample code for my site that was installed under the /blogs/ sub-directory:
if (!function_exists(‘userphoto_the_author_thumbnail’))
{
echo “no userphoto support”;
}

elseif (userphoto_exists($authordata))
{
userphoto_the_author_thumbnail(
”,
“”,
array(‘class’ => ‘authorphoto’,’border’ => ‘0’, ‘width’ =>70, ‘title’ => trim(get_the_author())),
‘/blogs/wp-content/plugins/user-photo/no_author_images.gif’
);
}