Paypal payment error

Users have mentioned the last week or so that the form freexes on them when they try to pay at the end of the form using the PayPal widget.  I have looked but see nothing wrong with the form's design to cause this.  Am I missing something?

 I ran a quick test to duplicate.  This is the error on PayPal that I get:

You have entered an invalid quantity value. A quantity value must be an integer greater than or equal to one.

Hi,

I am unable to recreate this problem here. Can you tell us which products did you select on your test when you received the Paypal error?

Thanks!