Posted
on Feb 9, 2012
(permalink)
I realized what was going on. I was using DataMemberBinding="{Binding Path=XXXXXXXXX, StringFormat={}{0:MM/yyyy}}" /> to display the data.
Because of this string format, it gives the impression that the values are duplicate.
Ex: 02/01/2010
02/05/2010
02/26/2010
are all being displayed as 02/2010 in the filter.