Orders missing in back office

[benignus]

I am trying to fix an issue with missing orders from the online store.
 

My PS version is 1.4.0.17 but I have made many custom changes and enhanced it.

Once I switched to a new hosting (virtual vps) I started having issues with orders going missing from the back office.

When I find the number of the order that is missing I receive an "Authorization accepted from PayPal" status of the order. I don't use a PayPal module, only cash on delivery or bank transfer. When I have a missing order with the PayPal status, I have to manually change the status to "Delivery" for the order to appear in the back office.
 

* If someone makes an order and it's not received if they submit a new one afterwards it's all fine.

* In some missing orders you can see the products but in others you can't

* When there is a missing order the client and I don't receive an e-mail acknowledgement of the receipt of the order (I have already stopped all spam blocking programs in my new hosting)

 

I ran quite a few tests and read everything I could find in the forum.

Here is an example of what I read about the problem - http://forge.prestashop.com/browse/PSCFI-7169, https://www.prestashop.com/forums/topic/178552-orders-not-showing-up-in-backorders/
 

I'm hoping that you would be able to let me know what could be causing this problem and how I could fix it.

 

Best regards,
Vlad