Thanks for the advice.
Just to let you know i found the correct line i needed to correct., i have also changed the 1st post as well to reflect this.
Code:
{include file="product_thumbnail.tpl" productid=$product.productid image_x=$product.image_x image_y=$product.image_y product=$product.product tmbn_url=$product.tmbn_url id="product_thumbnail"}
[img]{$ImagesDir}/zoom1.gif[/img]