Filter mashup by taxonomy?

Hello,

I am trying this code but it displays all the posts instead of only the taxonomy i selected. any ideas?

if ( function_exists( ‘pronamic_google_maps_mashup’ ) ) {
pronamic_google_maps_mashup(
array(
‘post_type’ => ‘schools’,
‘tax_query’ => array(
array(
‘taxonomy’ => ‘schoolcategory’,
‘field’ => ‘term_slug’,
‘terms’ => array(‘boxing’),
)
)
),
array(
‘width’ => ‘100%’,
‘height’ => 400,
‘map_type_id’ => ‘roadmap’,

)
);
}

Can it be done with the shortcode too?

thanks!