Quote Originally Posted by RodG View Post
Those seem to be typical settings for a server with moderate security (meaning that there may be times where one or more are too restrictive for the task at hand).

I don't see them being relevant to this issue though.

Still no luck with the error logs?

Cheers
Rod

I'm heading off to bed. Nothing more from me until late tomorrow. Hopefully you'll have found the cause by then :)
I did not find anything useful in the error_log. I am hoping once I understand DrByte's instruction and start the test that hopefully it will reveal something. I compared the files on the server to the ones in my downloaded 1.5.1 (just like I did before upgrade) and I don't see anything strange like file missing or different (that shouldn't be different). It's definitely a mystery but at least I am glad it's not affecting customer's ability to checkout.