TimThumb – Mimbo 3.0 – How to get it to resize the single.php orginal image

Anyone out there know how I can get Timthumb to resize the original single.php image. It works on the homepage and heres the code for that homepage image’s:

<?php echo get_post_image (get_the_id(), ”, ”, ” .get_bloginfo(‘template_url’) .’/scripts/timthumb.php?zc=1&w=350&h=169&src=’); ?>

I can get the image to resize by adding the same code to the single.php file but it just adds a resized version on top of the original – any way that i can have it just resize the original?