Duplicate Orders

We have experienced some duplicate orders that appear to be completely random.
The payments are not duplicated but there are two orders listed in the admin and the customer is notified of the second order.
The orders have identical info but with a new order #.
The duplicate does not occur right away, it occurs about 2-3 minutes apart.
Today one was generated 3min and 36 seconds after the original.
Two days ago one was generated 2min and 37 seconds after the original.
We have had about 8-10 occurrences over the last month.

I am a web designer and have installed several ZC stores and this is the only one that I have experienced this with.
Add-ons:
Ceon Manual Card - for all payments.
Ceon Advanced Shipper for all shippping
Image handler 3
edit orders v3.03
zen lightbox

The store has been live since about Oct 2010
The duplicating happened once before but went away. It lasted maybe a month.
It may have been fixed by the activity log reset that I performed.
I just performed another reset to see if that would fix it.

Any help would be greatly appreciated to say the least!

Just a follow up. After resetting the activity log the problem seems to have abated.
Any advice or help still would be appreciated.

Spoke too soon. The problem persists.
Noticed the latest duplicate purchase was made not using the CEON Credit Card module. It was paid by check.

I think it might very well have to do with your edit orders module. Try uploading a fresh orders.php file in admin to see if that resolves your issue.

Thanks for your response, ksookma. I tried that and it didnt appear to work. I am going to try uninstalling the edit orders for a week or two and see how long we can go without a duplicate.