For the first time ever today we hit a thousand unique yesterday we hit 890 and ob both days seen orders come through using the same coupon.oviously the second order fails but the.first order is out standing.do you thinkthat the server is overwhelmed,slow and then users are double clicking the process order button as they think nothing is happening?
[QUOTE]do you thinkthat the server is overwhelmed,slow and then users are double clicking the process order button as they think nothing is happening?[/QUOTE]
Very good possibility this is causing your customers to double click creating duplicates.
When you visit your site throughout the day does it always seem peppy, if you experience much fluctuation in site speed then you should consider making some changes.
We have been running in to the same duplicate order problems. Sometimes it seems it would have been easier to keep a couple of the smaller sites on a “shared” hosting package as a basic VPS just does NOT have enough power for CS. It goes back and forth on the forums as to some who think you need a VPS and others that say you do not. It is a tough line to know when to jump.
To top it all off, if you are using some of the cache suggestions from the forums or using “mysqli” then without a doubt when more people are on your site your site will drastically slow down and cause double orders.
Im just using files as the cache method at the moment! Had massive problems with memory allocation with the other cache methods. real pain tbh. I would have thought that with a VPS then the cart would be better…obviously not!
I am STILL getting duplicate orders and this is REALLY bizarre, I get them on our Credit Card payment AND Paypal I have sped up the cart by putting my php.ini to 256MB which has helped but duplicates are still coming through. 
Starting to get a little annoying!
Just tried ordering through our cart and it hangs big time when placing an order using Credit/Debit card payments, I am also finding that it redirects to the Paypal “We are redirecting you please be patient” screen even though our payment processor for Credit/Debit cards is not paypal.
Hello AmitP,
We are sorry to hear that you experience such a problem.
The problem requires the investigation on your server. Please contact us via Customer Help Desk and provide us with a temporary access to your server.
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Anastasiya Kozlova
CS-Cart Support team
Thank you, issue has been raised and already I believe your guys have been recreating the problem. Thank you
Thank you for the reply, AmitP
You are welcome. Please let us know if the provided solution helps you.
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Anastasiya Kozlova
CS-Cart Support team
I'm seeing duplicates on a daily basis, I am going to implement a suggestion here:
Duplicate orders - v1.x Issues & Troubleshooting - CS-Cart Community Forums
And hope this resolves the problem but this should really be fixed by the guys at CS-CART, I just tested and I managed to add 4 orders by just clicking on the 'place order' button in the final step of the checkout.