How to permanently set UPC value to empty instead of "0" for product combination in PS 1.6

[mouli90]

Hello,

I am running on PS 1.6.14 and using one Ebay import module. For each import I need the UPC fields of categories to be empty, however they are not. There is always value "0" and whenever I want to import the product, I have to manually delete the "0" from each UPC field of the product combination.  So I would like to ask if there is someone who could advise me what to do for permanent deletion of the "0" value and preventing it to show it again. Many thanks in advance

 

Jan