I am having trouble with a formula. Most of the time it calculates
correctly. It is a sumproduct formula which is supposed to count cells in a
range which are greater than 0 if the cells in a different range (column)
contain a certain word. Ie. count all cells in range XX if cells in range
YY = specific text. For some reason it does not count a few lines in the
spreadsheet. It comes back with 32 when it should show 33 etc. I have
narrowed down which rows are a problem - I'm just wondering if anyone has any
ideas why the formula would not count a certain row. Is it a formatting
issue? What things should I check for?? What kinds of things would cause it
to bring back an incorrect value?

Thanks very much!

Formula: =SUMPRODUCT(--('Shipped against rqd Nov08'!$AH$4:$AH$527="Bus Jet
OEM"),--('Shipped against rqd Nov08'!AP$4:AP$5270))