Invalid argument when using embed code in single.php (but other embed codes OK)

Hi guys

Receiving this error after adding one of the Embed Codes to my single.php file for a field called Classification (it's a dropdown field in the back-end), the error is:

Warning: Invalid argument supplied for foreach() in /home/esanctuary/webapps/dubaimalls/wp-content/plugins/directory/themes/default/single.php on line 42

The URL is:

I have added other custom fields successfully using embed codes, eg the telephone number on this page:

Could it be anything to do with the fact that it's a dropdown field (which has been populated) and the telephone number is just a text field, this is the embed code that I'm using, copied directly from the Custom Fields page in the appropriate part of the Directory plugin:

<?php if ( get_post_meta( $post->ID, '_ct_radio_4db1e8d56211a', true ) ) { foreach ( get_post_meta( $post->ID, '_ct_radio_4db1e8d56211a', true ) as $value ) { echo $value . ', '; }} ?>

Would appreciate any help or advice you can give on why this might be happening



(I'm using WordPress 3.1.1 and the latest version of the Directory plugin (downloaded today))