I run an ecommerce site built in Shopify and use PayPal Standard (UK) to take payments. Normally it works fine but I can see from my stats that up to 1/3 of my customers fill in all their details and then abandon the order often however trying again minutes or hours later. Because I have all their details I can see that this is failing at the payment stage and because some eventually get through I can see this is not fraud or failed cards. It has been suggested that PayPal "times out" and that this may be a reason. Is this a common level of problems? Any other suggestions or insights?