I am using Magento 1.9 and (this was an issue before too) there sometimes appear to be a lot of failed / pending orders when using PayPal Standard (other PP solutions don't work too well).
Sometimes we get money and payment is still marked as pending but most of the time it just says pending and customer does not pay / complete the order.
We identified one case with failed order, which was: a space after city name caused payment to fail, which we fixed. However, sometimes there would be like 10 complete orders in a row and some days it's like 10 PENDING PAYMENT orders in a row, upon contacting customers they just say that they were unable to pay for some reason and had no idea why too.
Any help is appreciated
We experienced this a lot from the end of September to current October 2015 which coincided with Paypal undergoing serious maintenance on their servers/system! Paypal have stated that they do not keep server logs for PP Standard so it is difficult to find the error/break point at their end. Our server access logs show the redirect to Paypal at the end of checkout and a GET request from Paypal's server for a header image on our site and then nothing i.e. no 302 back to the success page after IPN
Contacted customers state they have difficulty getting payment through, some trying up to three times and then success or they just give up!
It's as if the
Magento debug log shows request array with order details sent but no return IPN array from Paypal with transaction IDs
No errors are recorded in Magento system log nor error log