ahhhh, ok, I get it now.
the problem is that each form uses the same element name.
you can get around it by setting the failed redirect to pass the value of the eCart1_1_ID_Add form element as a querysting variable, then add an additional if statement around the validation show if code to only show if the ID in the query string is equal to the ID in the recordset.
send a copy of your page and i can tell you the code changes to make.