Zen Cart version: 1.5.0
PHP Version: 5.2.17 (Zend: 2.2.0)
MySQL version 5.5.19

Zen Cart recently recorded 7 identical orders (except for a unique order number for each) for one product. This hasn't happened before and no changes to Zen Cart have been made recently. The customer said they got charged for only one item but Zen Cart reports 7 approved transactions, each within a few seconds of each other. This issue is similar to the one omnicognate experienced here: http://www.zen-cart.com/showthread.p...negative-stock. However, the payment module is Authorize.net.

Is there a know bug in Zen Cart that may cause this? Any one know of a solution or ideas on where in Zen Cart can I start investigating this?

Thanks.