Intermittent Cart Problem

I have a client that seems to be having intermittent problems with their cart page. So far they've seen the problem once and they have had 1 customer experience the same problem.



I know my client uses both Firefox and Chrome, but he can't remember which browser he saw the problem in. He also doesn't know what his customer was using. I've tested his cart in FF, IE, Chrome, and Safari, but I can't seem to duplicate the problem.



What is going on is that when a customer adds a product to their cart they are redirected to the cart page. Both my client and his customer went to the cart page just fine, but when they got there, the quantity box of the product was missing. The amount was still there and correct, but the quantity was gone.



Both my client and his customer were still able to checkout so there was no loss of money, but obviously this is something he'd like to get fixed.



Unfortunately this isn't a problem I can duplicate so I have no idea what is going on. The reason for this post is to see if anyone else has experienced this problem and if they have, have they fixed it. Also, if anyone has any ideas on what is going on, I'd love to hear them.



Thank you for any help you can provide.



Brandon