The "In These Pages" field in the product download should be empty. (Note this field has been replaced in recent versions with "Add to Pages" ) This field is only used when assigning products to pages in an upload.
The Product download field "Product on Pages" will contain a list of pages that the product is assigned to. The format is PageName1|PageName2|PageName3 etc.
Note: You should not use the Product on Pages field and the In These Pages or Add to Pages at the same time in an upload file.
The Pages database table contains the actual assignment of all products. so you will find the products assigned to a page in the Pages download file in the field "Product Links". and will use the format Product1|Product2|Product3 etc. If 2 products have the same name then the sku will be added to the product name so it would be like this
Productname~sku|Productname~sku2 etc. This same format would be used in upload file if duplicate product names exist.
See
http://shopsite.com/help/10.1/en-US/sc/ ... ields.html for description of the Product download/upload fields Product on Pages and Add to Pages and the Page download/upload field Product Links .