Dropped transactions?

[Learners_permit]

I'm running oscMax v. 1.7 with an EchoNet gateway doing realtime credit card processing. Last week I was fortunate enough to have Ellen Degeneres mention my subject matter on her show with Beyonce. That put 150+ people into my shopping cart simultaneously for some hours with a record number of orders!

The problem is that I am now getting a few calls from people who say they ordered, but there is no record of their order nor any record of a transaction having been processed on their credit card. In all but one of these six cases, the person's account was correctly created, but the transaction never completed nor recorded. None of them received an order confirmation either. There's no liability because their cards were never charged and we don't store any credit card numbers in our database. The numbers go straight to EchoNet.

A few dropped transactions have also happened at other times of lower activity (say, 25 to 50 people in the cart simultaneously).

Here are my questions:

1. Is this due to the MySQL connections limit on my server? (This is my best guess. It was set at 300 and has now been raised to 600.)
2. Has anyone ever heard of osCommerce/oscMax occasionally "dropping" transactions?
3. What possible solutions are there beyond increasing the max MySQL connections limit, which I've already done?

In addition to that problem, I 've been getting occasional, intermittent phone calls from customers saying they can't fill out all the information in the cart. The checkout_shipping or checkout_payment page won't accept their data and go to the next screen. Does anyone have any information on this?

Thanks,
Peter Glickman
www.TheMasterCleanse.com