I've had some people email about this before but haven't been able to duplicate it on my end. An employee of mine (who's also been working with cscart since 2010) just had the same problem today and she sent me this email:
"I donâ€™t know why but placing an order is a complete pain in the a#$. I have the same problem that some of these people are emailing about. You place the item in the cart decide you want to look at another item and I am assuming hit the back button. When you enter all you info and hit submit NOTHING happens. You have to go back and clear your cart and start the process all over. It never use to be that way. I think we are losing orders because of this. "
Anyone else have this issue (that you know about) and have any ideas on the fix?