After migrating both my site and CSR to a new access provider my cart.php page no longer goes to my secure.checkout.php page. The only change that I can see is that I am migrating from a Apache Mod-SSL server to a C-panel set-up. Any suggestions?

Any chance some permissions didn't transfer? I am using a Powerstore to cart set-up. It worked with no issues before migrating the site. It works fine up to the cart page all data and images show up. The issue seems to be with the transition from insecure to secure server. The url is browngrotta.com

Please attach a copy of the cart page and i'll take a look.

http://www.browngrotta.com/WA_eCart/cart.php

It looks like your certificate hasn't been installed properly. You can't get to:

https://secure.browngrotta.com/checkout.php

You will have to fix that before the cart will go to the page.

My access provider reinstalled the CSR and says its correct. I noticed after my access provider moved over the site that I have no secure sub-directory under browngrotta.com. Should I create one and if so which files would go in it? Since cart.php is looking for the secure.browngrotta.com/check-out.php page. If I put it into a secure sub-directory it goes their with a Warning: require_once(web assist/framework/framework.php) . But at least it goes somewhere.

It appears the cert is installed properly now, but I still can't get to:
https://secure.browngrotta.com/checkout.php

I'm not sure how your server is set up. You'll have to ask your hosting provider how to transfer files to the secure server.

My hosting provider suggests placing required files in a secure subdirectory within the websites main directory so the CSR can find it. If that is the solution what files would I need to place in the sub-directory. Otherwise my provider has no idea. He transfer the files from the existing provider and everything is where it was and it did work before transferring

Your provider has to help you... this should go to a web page:

https://secure.browngrotta.com/checkout.php

it doesn't, so the files aren't in the right place. The hosting provider needs to fix that, there is nothing I can do to help since I don't know how the servers are configured.

Is it possible the difference is the moving of the site from an OS X server set-up to a Linux server set-up. In which uppercase/lowercase sensitivity could be creating the conflict. I noticed the OS X was much more forgiving then the linux server seems to be.

I couldn't say... is that the correct file name (case sensitive)? This is really a discussion you should be having with your hosting provider since they have the information to look into your theories.