[Plugin: Social Discussions] PHP warning invalid argument supplied foreach

I am seeing PHP warnings in the error log

PHP Warning:  Invalid argument supplied for foreach() in /home/sites/mysite.co.uk/public_html/wp-content/plugins/social-discussions/social-discussions.php on line 335

line 335 looks like it just inserts the post id

$post_data_custom = get_post_custom( $post->ID );
	foreach($post_data_custom as $key=>$val) {

so how can i fix this?

http://wordpress.org/extend/plugins/social-discussions/