I'm having a little issue with implementation... I uploaded the files, and the loading .gif shows up, but the page pops up an error message dialog that says "Status Returned - not found"

You can see for yourself here:
http://showcatcentral.com/cart/index...r_of_uploads=0

No idea what I'm doing wrong, but as you can see I've customized the template quite a bit... Any ideas? Thanks!