OK, now i understand, it was not clear before that this was only an issue if there was no tab (size) available for the item.
for items that do not have a size, is the inventory ID value the same as the prodID?
for this to work, it will need to be set that way.
you would need to edit the inventoryID recordset in advanced view, and create another condition for the where cluase:
OR invetoryid = paramProd
create a new parameter:
default value: -1
Runtime Value: $_POST['winkee_1_ID_Add']