Column Layout Grid for Product Listing

I have installed the Column Layout Grid for Product Listing in my Zencart on http://castlepictures.com . I get an "illegal access" message in all my product categories . Any idea what I need to do to fix this problem ?

DrByte's reply - " This is caused by mismatched versions of files.
That error appears when a script attempts to access system function files but is doing so via a non-standard approach.
In application_top.php, there is code to set to define IS_ADMIN_FLAG. You need to add that back in if it's missing, or add it to whatever custom code tools you've added in order to display information on the indicated pages. "

I know just about nothing about php files . Could you tell me what file / directory I need to change and the code I need to change it to ? Thanks for your help

Looked at your link and you have no categories setup???

I have now done a fresh instal of Zen 1.3 . How could I add my old products and categories ? I have a dump of my old SQL database .