Simple SEO URL (OLD version) [support thread]

[Craft Magick]

Your site is running php4, SSU does not support PHP4, it requires php 5. The fastest way to fix it for you now, is to go into includes/auto_loaders folders and remove any files SSU added (just compare with the same folder from SSU package)

Please bear with me and I'll try and provide as much info as possible to hopefully help someone troubleshoot this install for me...

I found out I am running PHP 5.2.8 so I modified my .htaccess file by just copying and pasting the contents of the .htaccess included with this mod to the end of my original one. Don't know if this was correct since I know nothing about .htaccess files but here's what my .htaccess file looks like now...

# Use PHP5 as default
AddHandler application/x-httpd-php5 .php


#### BOF SSU
Options +FollowSymLinks -MultiViews
RewriteEngine On
# Make sure to change "test_site" to the subfolder you install ZC. If you use root folder, change to: RewriteBase / 
RewriteBase /zencart/

# Deny access from .htaccess
RewriteRule ^\.htaccess$ - [F]

RewriteCond %{SCRIPT_FILENAME} !-f
RewriteCond %{SCRIPT_FILENAME} !-d
RewriteRule ^(.*) index.php?/$1 [E=VAR1:$1,QSA,L]
#### EOF SSU 

This is what now shows up in admin>extras now when I click on Simple SEO URL manager...

 Instruction SSU caches your categories/products names and links in order to reduce the number of sql queries and minimize the performance penalty on your server. That has its drawback, however. If you change your categories/products names, you will need to reset the cache to force SSU reload and update the names.
Cache Functions Reset all cache: Click here
Reset alias cache: Click here
Reset only products cache: Click here
Reset only categories cache: Click here
Reset only pages cache: Click here
Alias Functions Manage Aliases: Click here 

When I set SSU Status to TRUE In admin>config I get the following error in my store front when a link is clicked

Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, webmaster@zencrystals.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.
Apache/2.2.11 (Unix) mod_ssl/2.2.11 OpenSSL/0.9.8i DAV/2 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 Server at www.zencrystals.com Port 80 

I'm running zencart version 1.3.8a and PHP 5.2.8

Any ideas or suggestions would be appreciated