Thanks for the response.
The site hasn't had Magic SEO URL's installed until now, and they haven't worked since first being installed.
I believe the programs are functioning (hence not corrupted) since some things are functioning. (Though I reloaded them forcing binary transfer and it didn't help)
First, the .htaccess is being written. When going to the site, I can see in the headers that the old creLoaded urls are being redirected to the new url's with a 301 redirect prior to the 503 error being generated.
Interestingly, when the Magic SEO URLs is disabled, the urls it created do forward correctly (i.e.
http://www.saltyunderground.com/corals-2/ does redirect to the category page for ID #2).
This would indicate that the .htaccess file and server redirection is working correctly.
So, it appears that something in magic_seo_urls-5.php is causing the 503 error after the server redirects to the correct 'page'. Since the cache is being actively updated, it appears that the process is getting at least that far before failing.
The only error messages reported anywhere are similar to:
failed to open stream: No such file or directory /home/saltyund/public_html/includes/magic_seo_urls-5.php
Which appears normal as it simply creates the new file in the cache.
Turning off Suhosin is something our hosting provider is NOT agreeable to, and we aren't in a position to switch hosting providers.
Any help would be appreciated.
Thanks