Just thought I'd come back and let you know I've found a fix to the problem I was having where the cPath extension was incorrectly appended to the end of the URIs.

As Conor said, it is nothing to do with the URI mapping module, it's a problem in the zen_get_product_path function.

The code to fix is here:
http://www.zen-cart.com/forum/showth...aster+category

Hope this helps!