CC payments processed, no order logged

Hi,
In spite of over an hour spent reading and searching I cannot seem to find an exactly similar problem to mine, let alone a solution.
My situation is simply that on two different sites using Zencart, not the same versions, we have CC payments received and validated, but no corresponding order. We work with a very reliable payment gateway with a callback system sending infos to the site even if the client does not willingly click on "Return to the site", and we could never recreate the situation ourselves or get details from a client who had placed an order we had not received. Still obviously there are cases when the CC provider's communication back with our site does not occur. We use that provider with other sites using ZC and OSCommerce and never had this happen though, only on those two sites.
This is a major issue as we then have to track down the client through the email in the payment ticket and then ask what they ordered which does not look very professional...
Is there a way to change that ZC behavior so that even if something goes wrong we still have the order logged before the client is redirected to the CC gateway ?
Thank you for your consideration.

are these all hosted in the same server?
If not find out about firewalls

They are on the same dedicated server but some other sites on that same server do work fine, and the difficulty is that only SOME orders create that issue. With sample orders (we tried a lot) we could never recreate it.
I'm not sure if I can find what causes this for now, so I must find a way to change the order logic : there MUST be infos logged before the payment system calls the callback URL so that the order is logged even if things go wrong. I remember users complaining about a similar issue but could not find anything.
Thanks.

No, there isnt its all session stored..

this was so that you didnt get odd or double order numbers. and you dont get a bunch of orders created and NO payment made.

I understand the logic to want to avoid similar orders with only one or none paid for, however this hurdle is even bigger than having to delete non-paid orders as they translate into lost business.
Actually I'd only need to duplicate the check or wire transfer payments logic to the CC payment : log infos and then take care of payment.
Any idea if there was a contribution about such a customozation ? I seem to remember there was.

which cc module are you using thats causing this issue

We are using a French provider called Paybox but I'm pretty sure the issue is not their end, it occurs sometimes only with the callback, and i've heard this happen with Paypal as well as other CC providers such as 2CO and Worldpay.

It happens with paypal when its not setup correct, or when paypal.com chokes

2co I didnt know they were still in business...LOL
If this is working on some sites and not on others on the same server I would point towards internal settings on your site or in the paybox.com account for these accounts

In fact we have seen that issue for months and have tried everything to solve it to no avail - we could not even see it ourselves in any case. Until we find out we must find a way for our site to log infos so that we do not lose more business, as often we end up cancelling orders for clients we have no info or order about, this is a serious issue.
We need to change how ZC behaves until one day we hopefully find the cause.
Thanks.

IF THIS WORKS on site a,
but not on site B then you have something wrong in site B settings

better solution is to use real time processing and not have to worry about the IPN coming back.,

Our solution is real-time processing, but a third-provider solution where clients have to leave our site. This will not change.
Payment does work on all sites, except sometimes (maybe 1 order out of dozens), so finding the logic is not easy.
We are good developpers and are used to debugging, this is not an easy one.
Settings are simple in ZC for such payments and they are similar on all sites including on those never having an issue. It's more likely linked to a connection or firewall issue but then again we have tried everything so far.
The question is about logging data and finding possible hacks or modules that would have solved that issue earlier - I know several people had it.

We are finding the exact same thing you described. It is only recently, before that there was not a problem. I did just add the shipping tracking mod, master password, and superorders. Could one of them be causing the issue?

Not sure if it could be for you, however we have none of these installed on our sites.
I still need to find a way to log order infos when the client chooses to pay by CC.

After more searches my question simply boils down to knowing if a contribution exists for Zencart like that one for OScommerce, that solves the exact problem I am facing :

www.oscommerce.com/community/contributions,1168

Has anybody installed such a modification on their site ? I am positive this is an issue encountered by several people...Thanks.

This also underlines the situation which remains a major problem with Zencart and may lead to orders and business loss :

www.oscommerce.com/community/contributions,871

Hi,
Did you get a solution, or implement a modified version of the OSC solution (http://www.oscommerce.com/community/contributions,1168)?