drop down list with formula

Hi,
I'm using a yes/no drop down list in cell C8 with the formular below.
If I get rid of the drop down and just type in "yes" in cell c8, it works fine, however if I use the dropdown, the formula does not work.

=SUM(IF((C5>=1)*(C8="Yes"),'Business Rules'!G4,0))

Thanks,

for me its working correctly. may be you have used a space after the "yes" like this "yes " in the drop down box.

Brilliant - thanks Sathaha, it was the space.

I'll watch out for that one in future.

Thanks very much