Invalid taxonomy when using get_terms

hi everyone,

I have developed a working template which uses a custom taxonomy “restaurant_menus”.

I making a variation of the theme to display to mobile devices however the same code does’t retrieve the taxonomy for the mobile template and if i print the object i see: WP_Error Object ( [errors] => Array ( [invalid_taxonomy] => Array ( [0] => Invalid taxonomy ) ) [error_data] => Array ( ) )

the code i’m using is:

<?php $taxonomy = 'restaurant_menu';
		$terms = get_terms( $taxonomy, array('parent' => 0) );
		if ($terms) : ?>

		<article id="Menus">

			<h1><?php _e('Menus', 'bigLampBrewery') ?></h1>

			<img class="alignright menu-image" src="<?php echo get_stylesheet_directory_uri(); ?>/img/Keelman_Menus.jpg" alt="The Keelman Restaurant Menus" width="169px" height="253px">

			<?php foreach($terms as $term) { ?>

		    	<div class="menu-select row" id="<?php echo $term->term_id; ?>">
		    		<span><?php echo $term->name ; ?></span> 

		    		<span class="description"><?php echo $term->description ; ?></span>

		    		<a class="button" href="<?php  echo esc_attr(get_term_link($term, $taxonomy));  ?>" title="View Menu" ><?php _e('View Menu', 'BigLampBrewery') ?></a> 

		    	</div><!--menu-select-->

			<?php } ?>

			<br class="clear" />

		</article><!-- /menus-->

Can anyone explain why this doesn’t work?

Thanks