Pelvis

Thanks! Solved was my mistake
Confusing folders and I put a file that had to come to the "front/modules" folder in "admin/modules" folder to.
I had inside the folder
/catalog/admin/includes/modules/cfg_modules/
2 files 
1. st_tax_below_price.php (this is only needed in "front/modules" folder and was causing the error)
2. cfgm_store.php
 
Thanks !

ATTENTION
Attention with the Last version of this Contrib.
Our Site was signed with red Flag from Google.
Google has found Malicious Software (Malware) in Parts of Code in our Site.
The Last Contrib that we had installed was the Upgrade of "Who's Enhancement"
The reason was due to the old API "ipinfodb.com".
So our Administrator has run a Program Called "I SCANNER" in our Server.
And VOILÀ the Program has reported a "Java Script Code" that can run from a remote source.
----------------------------------
From: iScanner 0.7 <iScanner@localhost>
Date: 2011/10/8
Subject: iScanner 0.7 report for localhost
To: "xxx@gmail.com" <xxx@gmail.com>
 
 
Hostname: localhost
Directory: /home/xxx
Extensions: htm, html, php, js
Log file: infected-09:43:55-08.Oct.log
 
 
/home/XXX/public_html/
Admin/whos_online.php
[2.3] (<script.+?src\s*=\s*['\"]?(?:ht|f)tp.+?>(?:.*?<\/script>)?)
Javascript code from remote source detected.
---------------------------------------------------------------------------
 
Generated by iScanner 0.7 (db:0.2.0) in Sat Oct 8 09:44:16 2011
Copyright © 2010 iSecur1ty <http://iscanner.isecur1ty.org>
 
 
 
After that we Installed Back the Old Version 3.5.5 (2 fixes up from Steve Dallas) and everything was fine also no report from "I SCANNER".
Also be Careful !!