I am using zencart 1.3.9.h.

I have a live test site, local Ubuntu LAMP server and I have WAMP on my workstation.

I normally develop my changes on the WAMP workstation and then upload the delta files (all changes since Aug 1, 2011) to the test server and Ubuntu (but do not overlay the configure.php files).

Prior to today's upload the Admin area worked on both the lives test and Ubuntu servers. Now on the live test server and the Ubuntu server the Admin area gets an immediate HTTP 500 error yet the WAMP workstation's Admin area still works.

FYI, I also overwrite all zencart tables with the test data from the WAMP workstation but I update the SMPTP mail server in the configuration table where configuration_id = 249.

I have verified that the configure.php file for the Admin area (on both servers) have the correct URLs and MySQL settings.

Also, my live test site is hosted on GoDaddy.com and so I do not have any control over the permissions of files but I have full control over my Ubuntu server's permissions.

In general, where should I start looking for why the Admin areas no longer wok on two out of three installs?

TIA for any helpl you can provide.