I searched the forums but did not see this addressed. It was not addressed on the Smack Digital site either.
When you use CDSEO Pro and disable Clean URLs in X-Cart, X-Cart does weird stuff to existing Clean URLs when you modify certain pages/products. This breaks the functionality of CDSEO Pro.
BCS Engineering has a fix for this regarding product pages:
https://support.bcsengineering.com/index.php?_m=knowledgebase&_a=viewarticle&kbarticl eid=272&nav=0,1,17
But I was still having problems with Static Pages. In admin/pages.php, I made this modification that seems to have fixed the problem. Under // Insert/Update Clean URL, I commented out the code executed by the if statement:
if ($config['SEO']['clean_urls_enabled'] == 'N') {
/*
// Autogenerate clean URL.
$clean_url = func_clean_url_autogenerate('S', $clean_url_pageid, array('title' => $pagetitle));
$clean_url_save_in_history = false;
*/
}