Missing Orders

Site has not been upgraded, it was an original install by the hosting company.
PHP: 5.2.17; MySQL: v5.1.56; HTTP Server: MS-IIS/7.5
Plugin's installed: Easy Populate; Stock by Attribute; Zen Lightbox
Responsive Template: Mobishop
Payment Modules: Authorize.net (SIM); Free Order; Check/Money Order; Paypal Website Payments Standard
Site is Live at: https://www.CoghlinAndUpton.com

What is happening is that a customer will create an order, get redirected to the necessary payment processing solution and the payment will be made and my client is notified through Zen Cart that a payment has been made. However, when he logs into Zen Cart to view the order, there isn't one generated.

It has been relatively random and I recall searching for this problem previously and found that PayPal Standard may be the cause, however my client is unwilling to move to a pay version... he'd rather call the customer when the order isn't there to get the order verbally.

However, recently (since the beginning December), he's noticed that there have been payments made through his banking solution (ie, not PayPal) and the orders are not being generated.

Any help/suggestions is welcome.

Thanks all.

A few things of note here:

a. Using PayPal Payments Standard makes you reliant on a number of things that can easily go wrong if the server and other factors aren't set up properly. One of the symptoms of that is orders not showing up in the store because the final activation doesn't happen due to those misconfigurations.
The simplest fix for that is to switch over to using PayPal Express Checkout ... (which has the same fee structure as PayPal Standard) and provides a better experience to the customer anyway.
Switching is simply a matter of clicking Remove on PayPal Standard and clicking Install on Express Checkout and adding your PayPal credentials (API signature and username and password). There's a link in the help text next to the Install button explaining it, with a convenient link to obtaining credentials too.

b. The sudden problem of broken transactions since beginning of December is probably connected to the POODLE SSL problem internet-wide. To fix your store, simply follow the instructions here to make a simple fix to a couple files: http://www.zen-cart.com/showthread.php?214916-Important-announcement-about-POODLE-and-payment-security

c. It's probably worth taking a look at what errors are occurring on the site, and fixing those. You can find the myDebug-xxxx.log files in the /logs/ folder, using FTP. Explained more here: http://www.zen-cart.com/content.php?124-blank-page

Thanks DrByte. I have done the following...

a) recommended to my client to switch to PayPal Express (thanks for this recommendation).

b) Have searched the PHP files and commented out the lines as outlined in the article. We will test over the next couple of days.

c) And finally, I have looked at the DeBug files... I didn't realize that they could accumulate so fast :blink: and will monitor in the future. Most of them are warnings prior to this summer and were dealt with at the time.
There were a couple of "fatals" however but none close to December, the last one being in mid-September... however I will track all these problems down.

Again, thanks for your suggestions and direction.

Sincerely,
Seaghan