(This is for if you have the stylesheet error with gss.xsl)
Here is why this addon won't work with zencart. You don't need to move anything anywhere or do anyother hack except to change the .htaccess file under your "includes" folder.

/web-site-root/includes/.htacess

on line 26 you will find:
<FilesMatch ".*\.(js|JS|css|CSS|jpg|JPG|gif|GIF|png|PNG|swf|SWF)$">

Change the line to:
<FilesMatch ".*\.(js|JS|css|CSS|jpg|JPG|gif|GIF|png|PNG|swf|SWF|xsl|XSL)$">

You are by doing that allowing the filetypes *.xsl and *.XSL to be accessed by an external browser.

My .htaccess version is:
# @version $Id: .htaccess 16111 2010-04-29 22:39:02Z drbyte $
So perhaps that is why on zencart 1.38 it works and not on the newer 1.3.9a.

drbyte is working some late hours, send him some coffee :)


MODERATOR NOTE: xsl has been added to the .htaccess for v1.3.9f and newer.