Session randomly expiring on final step of checkout process

[laurelsstitchery]

NOTE: When making a new post, be sure to include relevant information such as:
What version of Zen Cart are you using? v151
Has your site been upgraded? When? From what version(s)? no
What version of PHP and MySQL is your server using? (See Admin->Tools->Server Info) PHP 5.3.27 MySQL 5.1.56
WHEN did the problem "start"? How does that compare with other events of your hosting company, changes you've made to your site files/addons, or your admin settings, etc? My host upgraded from PHP 5.2 to 5.3.27 and immediately, a few customers began complaining that their cart would timeout when they hit the final button to complete their order. The PHP upgrade was the only thing that has changed on my installation for several months.
Please post your site URL* so we can take a look at it. This is especially important if you're encountering display/layout problems, so the problem can be seen directly. laurelsstitchery.com
If you're encountering problems that could be related to your server or hosting company, include the name of your hosting company (not their URL). Dreamhost
HAVE YOU LOOKED IN THE FAQ AREA for answers to your question? (ie: a search for your error message or what you want to edit/change, etc) yes
Have you searched the FORUM for your error message or for answers to the question you're asking? yes, but the other threads are older and no one mentioned having upgraded PHP recently

As mentioned above, my host upgraded PHP from 5.2 to 5.3.27. Of course, this happened during my Thanksgiving sale, so the site was getting a lot of traffic. Within the hour, I received an email from a long-time customer complaining that the cart had timed out when she hit the final button to complete her order. After a couple of attempts, she was able to log back in and complete her order. I wrote it off to her walking away for a while and the normal time-out occurring.

On 11/30, I was entering my usual batch of manual orders. After a few completed correctly, I got the same session time-out error. A couple of times, I was able to log right back in and complete the order and a couple of times, I had to dump all cookies before I was able to log back in. Highly annoying.

The error is still occurring today. I'm convinced this is the fault of the PHP upgrade. I don't know where to start on getting it fixed. Any help would be appreciated.

[laurelsstitchery]

Hoping someone will see this and help. Error still occurring.

[chibipaw]

Same exact problem here. Can't seem to debug it as there are no error in any of the logs. It also only happens to some session, but not all.

[laurelsstitchery]

Replying again to see if anyone can help.

Same exact problem here. Can't seem to debug it as there are no error in any of the logs. It also only happens to some session, but not all.

[picandnix]

Replying again to see if anyone can help.

Hi. A couple of extra questions;
Have you contacted your host about this?
Have you any checkout mods (COWOA, FEC or the like) running in your store.
Does this issue happen in all browsers?
Any error logs being generated?

[laurelsstitchery]

Hi. A couple of extra questions;
Have you contacted your host about this?
Have you any checkout mods (COWOA, FEC or the like) running in your store.
Does this issue happen in all browsers?
Any error logs being generated?

Checkout mods? Nope
Browsers? All that I've tried - Chrome, Safari, Firefox
Error logs? Nope

[laurelsstitchery]

Checkout mods? Nope
Browsers? All that I've tried - Chrome, Safari, Firefox
Error logs? Nope

Missed a question in previous reply:
Haven't contacted host (dreamhost) because they're just going to disclaim responsibility and send me back here

[lat9]

Does it matter what payment method is used? What payment methods do you have enabled?

I'm "assuming" that when you say the timeout occurs at the last step of checkout, it's when the customer clicks the "Confirm Order" button from the checkout_confirmation page -- is that true?

Have you made any changes to the admin Configuration->Sessions settings? Posting your current values here might help.

[laurelsstitchery]

Does it matter what payment method is used? What payment methods do you have enabled?

I'm "assuming" that when you say the timeout occurs at the last step of checkout, it's when the customer clicks the "Confirm Order" button from the checkout_confirmation page -- is that true?

Have you made any changes to the admin Configuration->Sessions settings? Posting your current values here might help.

I've only experienced the error when using a credit card. Yes, it's when I click the confirm order button. It immediately goes to a timeout error page, but not every time. It's random. I'm using the built-in Authorizenet module for credit cards. I haven't made any changes to the sessions settings. The only change was the upgrade to PHP. I did a live chat with dreamhost today and their solution was to downgrade back to PHP5.2, which I have done and the error is no longer occurring. I can't stay on 5.2 forever though.

[laurelsstitchery]

Does it matter what payment method is used? What payment methods do you have enabled?

I'm "assuming" that when you say the timeout occurs at the last step of checkout, it's when the customer clicks the "Confirm Order" button from the checkout_confirmation page -- is that true?

Have you made any changes to the admin Configuration->Sessions settings? Posting your current values here might help.

Here are my Configuration->Sessions settings:
Session Directory /deleted/for/privacy/catalog/cache
Cookie Domain True
Force Cookie Use False
Check SSL Session ID True
Check User Agent False
Check IP Address False
Prevent Spider Sessions True
Recreate Session True
IP to Host Conversion Status true
Use root path for cookie path False
Add period prefix to cookie domain True