There are instructions here for clearing old items from the dropdown lists:

http://www.contextures.com/xlPivot04.html

RADO wrote:
I will appreciate advice on how to update pivot table
items in Excel 2002. My pivot table is based on the named
range, which I am updating from time to time using
RefreshTable method. The problem is that while the pivot
table updates data correctly, it does not update pivot
items, showing me totally irrelevant list of values. For
example, if I downsize the table from 10 records to 1, it
still shows me all 10 items in the field filter. It does
not make any sense; is it a Microsoft bug, or am I missing
something?

--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html