Hi Ray. Here are the steps to reproduce the error.
1) You will need to clear all PayPal login credentials / history from your browser history
2) Customer visits www.sportsmedicalcertificates.com
3) Clicks "Get Started"
4) Complete's all 5 Steps of the Health Screening Form
5) Upon completing Step 5, they then select "Add to Basket"
6) Then "Continue" when presented with the Checkout page
7) The customer then reported clicking their browser "Back" button when presented with the Pay by Card option on PayPal
8) Upon returning to the Sports Medical website, we note that the form reference is then missing from the order (as previously detailed on the checkout page in step 6)
This happened again in a test I ran this evening - order 4050 - but then didn't happen with an additional test I ran but I wonder if that was to do with the PayPal pages being in my cached history.
If you recall, you installed a log script on, I think it was pp_confirm.php so I was wondering if you'd be able to see what was the difference between the two orders that did the same thing (as described above) - 4046 (a live customer) and 4050 (my test) - and my last test which didn't - 4051?
I'm free tomorrow or Friday, if required, for a Premier Support session but was hoping you might be able to spot what's happening from the log files.