Mashup won't load

I load the function

pronamic_google_maps_mashup(
        array(
            'post_type' => 'praktijk'
        ),
        array(
            'width'          => 300,
            'height'         => 200,
            'nopaging'       => true,
            'map_type_id'    => 'satellite',
            'marker_options' => array(
                'icon' => 'http://google-maps-icons.googlecode.com/files/photo.png'
            )
        )
    );

within a function in functions.php.
The Mashup map is not loading, it is showing a big white space but no map is loading, however when I just load the standard pronamic_google_maps() function it loads the static one perfectly.

And when I’m inserting the mashup function directly in my template-page file it is also loading ok.

But I need it to be running from within the function in my functions.php.

What should I do/check?

http://ww.wp.xz.cn/plugins/pronamic-google-maps/