Possible Duplicate Slug

Hi WordPress brain boxes!

So today I updated to plugins on my wordpress site, “Relevanssi” and “WordPress Statistics” and since I updated these my custom post type pages won’t work any more. The URL would be /courses/the-course-name/ but that brings up Godaddy’s defualt 404 page instead of my WordPress 404 page.

I tried deactivating all plugins to see if this works but to no avail. I then changed the permalinks from “Postname” to “Default” and this worked fine but when I went back to “Postname” it was not working again…

I then changed the slug of the custom post type in the functions.php and just added an extra S to /courses/ and this seemed to work but the obvious problem being I want it to say /courses/ not /coursess/.

Has anyone got any idea what I can do to resolve this please. We have just started using Google Adwords aswell so need the URLs to be back to how they where.

Thanks, Terry