I have removed my previous replies made during my attempts to rectify this. Ultimately I settled the php part of the discrepancy by swapping my 5.2.0 file for the one you sent me to that defined the version as 5.3.0. I then contacted my web host who upgraded my php to 5.3.0 to match my index.php file.
This has enabled my homepage link to: ... .com/index.php?rt=product/category&path=65 to land on a page in our cart, but it has no content and reports that that page cannot be located.
So our site is down and the link we had to the dashboard when we created the site last year is also dead ... so this problem is due to some other cause. Please help me find that and get our cart back online. Thank you.