Yes! In the registration manager, open one of your events and you\'ll see all of the custom fields listed at the bottom. You have to select the custom fields you want to show for that event. So this way you can use a custom field for only the event(s) you want it on.
Tom, Is it possible that you have only one custom field which is called Custom in your screenshot?
I know that for free events, this functionality works fine for me, but I only have one field. I wouldn\'t think that your selection of a payment gateway would impact upon the operation of custom fields, but maybe....