Sagepay not always returning back to Success URL

[spitlikethis]

This is a problem that has been happening to me for several weeks now.

I have had my site online using the same payment system / URL etc since 2004. Recently, I started receiving "Payment Success" notifications but no order details in the back-end of my site.

I have scoured various forums on Oscommerce but cannot find a solution.

I have asked SagePay for help but they are saying that it is being returned.

Anyone else experienced this? SagePay are denying all knowledge of any problem but I don't believe them.

Incidentally, it ONLY happens with Visa/Debit payments, approx 30% of the time.

Thanks. It's annoying - I'm actually looking into moving over to Worldpay.

PS Would changing the success URL in the script from the checkout_process.php to checkout_success.php - like it is for PayPal - help??