Excel Pivot Table

Excel Pivot Table ? Selected Items

Why Excel does not keep the same selected items in the pivot table?
For instance, my pivot table selects just the accounts that are Asset Accounts. I mark just the accounts that I want in the drop down list items. Well when I refresh the pivot table it always adds other accounts that I do not want to see. What I notice is those accounts where not showing in the data base when I first build the pivot table.
How can I keep just the selected items?