Theme options not passing data to sanitize callback

I have the following code and while the form displays correctly as an options page under ‘appearance’, the values types into the input fields do not get written to database.

A test of the $input array received by the sanitize function reveals it to be empty, yet a check of the $_POST array at the same place shows data to be correctly submitted with the form, just that it doesn’t make it into the $input array… and result is the database isn’t being updated and values not stored.

/* ------------------------------------------------------------------------ *
 * Setting Registration
 * ------------------------------------------------------------------------ */   

function bm_theme_menu() {  

    add_theme_page(
        'Blue Mountains Options',		// The title to be displayed in the browser window for this page.
        'Blue Mountains Options',		// The text to be displayed for this menu item
        'administrator',				// Which type of users can see this menu item
        'bm_theme_display_options',		// The unique ID - that is, the slug - for this menu item
        'bm_theme_display'				// The name of the function to call when rendering the page for this menu
    );  

} // end bm_theme_menu
add_action('admin_menu', 'bm_theme_menu'); 

function bm_theme_display() {
?>
    <!-- Create a header in the default WordPress 'wrap' container  -->
    <div class="wrap">
        <div id="icon-themes" class="icon32"></div>
        <h2>Blue Mountains Options</h2>
        <p class="description">There are currently no options. This is just for demo purposes.</p>
        <!-- Create the form that will be used to render our options -->
        <form method="post" action="options.php">
            <?php settings_fields( 'bm_theme_display_options' ); ?>
            <?php do_settings_sections( 'bm_theme_display_options' ); ?>
            <?php submit_button(); ?>
        </form>
    </div>
	<?php
} // end bm_theme_display  

/**
 * Initializes the theme options page by registering the Sections,
 * Fields, and Settings.
 *
 * This function is registered with the 'admin_init' hook.
 */
function bm_initialize_theme_options() {
	if( false == get_option( 'bm_theme_display_options' ) ) {
		add_option( 'bm_theme_display_options' );
	} // end if
    // First, we register a section. This is necessary since all future options must belong to one.
    add_settings_section(
        'bm_global_info',					// ID used to identify this section and with which to register options
        'Blue Mountains Global Info',		// Title to be displayed on the administration page
        'bm_general_options_callback', 		// Callback used to render the description of the section
        'bm_theme_display_options'			// Page on which to add this section of options
    );
    // Next, we will introduce the fields for toggling the visibility of content elements.
	add_settings_field(
		'cricos_provider_id',				// CRICOS Provider ID
		'CRICOS Provider ID',				// The label to the left of the option interface element
		'bm_cricos_provider_callback',		// The name of the function responsible for rendering the option interface
		'bm_theme_display_options',			// The page on which this option will be displayed
		'bm_global_info',					// The name of the section to which this field belongs
		array(								// The array of arguments to pass to the callback. In this case, just a description.
			'Your CRICOS Provider ID'
		)
	);
	add_settings_field(
		'abn_no',							// CRICOS Provider ID
		'ABN Number',						// The label to the left of the option interface element
		'bm_abn_no_callback',				// The name of the function responsible for rendering the option interface
		'bm_theme_display_options',			// The page on which this option will be displayed
		'bm_global_info',					// The name of the section to which this field belongs
		array(								// The array of arguments to pass to the callback. In this case, just a description.
			'Your ABN Number'
		)
	);
	add_settings_field(
		'contact_phone',					// CRICOS Provider ID
		'Contact Phone Number',				// The label to the left of the option interface element
		'bm_contact_phone_callback',		// The name of the function responsible for rendering the option interface
		'bm_theme_display_options',			// The page on which this option will be displayed
		'bm_global_info',				// The name of the section to which this field belongs
		array(								// The array of arguments to pass to the callback. In this case, just a description.
			'Your Primary Contact Phone Number'
		)
	);
	add_settings_field(
		'copyright_from',					// CRICOS Provider ID
		'Copyright starting from (year)',	// The label to the left of the option interface element
		'bm_copyright_from_callback',			// The name of the function responsible for rendering the option interface
		'bm_theme_display_options',			// The page on which this option will be displayed
		'bm_global_info',				// The name of the section to which this field belongs
		array(								// The array of arguments to pass to the callback. In this case, just a description.
			'[yyyy] Year from which to start copyright notice in footer'
		)
	);
	// Finally, we register the fields with WordPress
	register_setting(
		'bm_theme_display_options',
		'bm_theme_display_options',
    	'bm_sanitize_display_options'
	);
/*
	register_setting(
		'bm_theme_display_options',
		'cricos_provider_id'
	);
	register_setting(
		'bm_theme_display_options',
		'abn_no'
	);
	register_setting(
		'bm_theme_display_options',
		'contact_phone'
	);
	register_setting(
		'bm_theme_display_options',
		'copyright_from'
	);
*/
} // end sandbox_initialize_theme_options
add_action('admin_init', 'bm_initialize_theme_options');  

/* ------------------------------------------------------------------------ *
 * Section Callbacks
 * ------------------------------------------------------------------------ */   

/**
 * This function provides a simple description for the General Options page.
 *
 * It is called from the 'sandbox_initialize_theme_options' function by being passed as a parameter
 * in the add_settings_section function.
 */
function bm_general_options_callback() {
    echo '<p>Setup global information for use on the website</p>';
} // end sandbox_general_options_callback  

/**
 * This function renders the interface elements for toggling the visibility of the header element.
 *
 * It accepts an array of arguments and expects the first element in the array to be the description
 * to be displayed next to the checkbox.
 */
function bm_cricos_provider_callback($args) {
	$options = get_option('bm_theme_display_options');
    // Note the ID and the name attribute of the element should match that of the ID in the call to add_settings_field
    $html = '<input type="text" id="cricos_provider_id" name="cricos_provider_id" value="' . $options['cricos_provider_id'] . '" />';  

    // Here, we will take the first argument of the array and add it to a label next to the checkbox
    $html .= '<label for="cricos_provider_id"> '  . $args[0] . '</label>';  

    echo $html;  

} // end sandbox_cricos_provider_callback
function bm_abn_no_callback($args) {
	$options = get_option('bm_theme_display_options');
    // Note the ID and the name attribute of the element should match that of the ID in the call to add_settings_field
    $html = '<input type="text" id="abn_no" name="abn_no" value="' . $options['abn_no'] . '" />';  

    // Here, we will take the first argument of the array and add it to a label next to the checkbox
    $html .= '<label for="abn_no"> '  . $args[0] . '</label>';  

    echo $html;  

} // end sandbox_abn_no_callback
function bm_contact_phone_callback($args) {
	$options = get_option('bm_theme_display_options');
	$phone = '';
    if( isset( $options['contact_phone'] ) ) {
        $phone = $options['contact_phone'];
    } // end if
    // Note the ID and the name attribute of the element should match that of the ID in the call to add_settings_field
    $html = '<input type="text" id="contact_phone" name="contact_phone" value="' . $phone . '" />';  

    // Here, we will take the first argument of the array and add it to a label next to the checkbox
    $html .= '<label for="contact_phone"> '  . $args[0] . '</label>';  

    echo $html;  

} // end sandbox_contact_phone_callback
function bm_copyright_from_callback($args) {
	$options = get_option('bm_theme_display_options');
	$year = '';
    if( isset( $options['copyright_from'] ) ) {
        $year = $options['copyright_from'];
    } // end if 

//print_r($options);
    // Note the ID and the name attribute of the element should match that of the ID in the call to add_settings_field
    $html = '<input type="text" id="copyright_from" name="copyright_from" value="' . $year . '" />';  

    // Here, we will take the first argument of the array and add it to a label next to the checkbox
    $html .= '<label for="copyright_from"> '  . $args[0] . '</label>';  

    echo $html;  

} // end sandbox_contact_phone_callback  

function bm_sanitize_display_options( $input ) {
echo "INPUT:<br>\n";
print_r($input);
echo "DONE!<br>\n";
    // Define the array for the updated options
    $output = array();  

    // Loop through each of the options sanitizing the data
    foreach( $input as $key => $val ) {  

        if( isset ( $input[$key] ) ) {
            $output[$key] = esc_url_raw( strip_tags( stripslashes( $input[$key] ) ) );
        } // end if   

    } // end foreach  

    // Return the new collection
    return apply_filters( 'sandbox_theme_sanitize_social_options', $output, $input );
} // end sandbox_theme_sanitize_social_options

Thanks in advance… Gut feeling is this is something so obvious I’m just not seeing it!

Cheers