integrating with Post Tiles plugin

Am really hoping this can be done as this plugin would be EXACTLY what I’m after.

I’m using a plugin called Post Tiles which pulls the featured image from a post and displays it as a background image.

In the coding of the Post Tiles plugin I have the following code…

$thumb = wp_get_attachment_image_src( get_post_thumbnail_id(), array(562,471));

I’m trying to modify the code to pick up the secondary image and every time I try to use the “MultiPostThumbnails::get_post_thumbnail_id(‘post’, ‘secondary-thumbnail’, get_the_ID());” code all I get is a white screen.

I tried the following…

$thumb = wp_get_attachment_image_src( MultiPostThumbnails::get_post_thumbnail_id(‘post’, ‘secondary-thumbnail’, get_the_ID());

…but no joy.

Any guidance would be appreciated.

http://ww.wp.xz.cn/extend/plugins/multiple-post-thumbnails/