Nile,
This is just an update. I have more work to do on your much appreciated suggestions. I missed your earlier post. Thank you for bring it to my attention. And thank you for your continued interest in this problem.
I use sessions on this server regularly. Additionally, the duration from setting the session index to trying to retrieve it on this site is typically just a second or so, so timing out I think we can rule out.
No, I would not expect anyone here to examine thousands of lines of code. So I do try to distill the problem. That is why I excerpted the page code. What I deleted were simply many many entries of the array. The PHP logic and syntax were preserved. It is a bit more than a sliver. Let me see how much more I can pare it down and still create the problem.
I'll be back with more info, though possibly not today.
A.

