Advanced filter to get unique values

Hi all,
Referring to the attachment below, I am trying to get the unique numbers in the B column. Most of the numbers in that B column appear more than once, and I would like to get a different column to display only the unique records. So wanted to use the Excel built-in method of filtering (Data->Filter->Advanced Filter) and (after having selected all the numbers in the B column, excluding the "Internal_PN" column header), I have used the options "Copy to another location" and "Unique records only" in order to obtain (on column E) the needed result.
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It works fine except for the first value in the column. I get the 101026 number twice. All other numbers in the original column appear just once on column E, except for this very first number which insists on appearing twice. I am using excel 2003, but I noticed the same in excel2007, so it must be something I am doing wrong.

Any help will be greatly appreciated.

Best Regards,
Cristian