I've got two or so orders that were authorized in authorize.net, but didn't register as orders in Magento. Any one have any ideas about debugging this particular kind of issue? Payment bridge is not being used currently.
The solution to this is likely going to be found in your PHP error logs and/or Magento exception log. Most likely what is happening here is after Magento enters the place-order step of processing an order (i.e. it is all ready to process payment and save) and has obtained the authorization, a fatal error of some sort is occurring.
Most of the time when I've seen this it has been due to some poorly written code in an observer which is catching one of the events fired between when the authorization takes place and the order save transactions commit. This poorly written code may be assuming something or not handling errors properly, and when it runs into a fringe case it kills the order, but after the payment has been authorized.
Because of this risk, I recommend implementing these sort of observers in the events fired after the order save transaction has been committed. This way, if an error does occur, the error merely white screens and the customer's order actually goes through. Obviously not a solution to not handling fringe cases properly, but good risk aversion. :)