I have a date in cell a1 such as 09/08/09

I have a helper cell b1 that is =Text(a1,"YYYY")

B1 displays 2009

In a cell b8, I have the following =sumproduct((year=b1)*(store=b3)*
(sales)

I get an error. When I simply enter the year into b1 without the text
formula, I get the correct sumproduct results.

What can I do to leave the text formula in? Excel 2007

Thanks a bunch everyone!