We have a Magento e-commerce site that's interacts with our Point of Sale program. When an online order is produced, the systems creates an xml file and inserts it into a folder on the web host server and then this file is downloaded into our Point of Sale. The system works correctly when the order is paid for using eWay however there are some inconsistencies when the order created is paid for using PayPal. When a PayPal order is produced, the xml file is sometimes produced and stored in the correct folder however at other times, this xml file is not produced at all. The problem only occurs for PayPal orders, not eWay orders and it only happens sometimes, not all the time.
I know that my question only gives a general description of the problem but I wondered if anyone has come across this issue before and whether any advice could be given as to why it may be happening?
I'd be really grateful for any help.