Many thanks for the help.. I ran the php info code and was the same as on admin: PHP Version 5.2.17 (ZenCart 1.3.8a)

I had run into a PHP version issue about a year ago, installed the php patches and has been up and running since.. but possibly something has changed recently..

I wasn't able to find any issues with files, and DB seems fine (admin working), so with the suggestions regarding php version, I'm hoping an upgrade to latest ZenCart Version may fix..