I have the following formula entered into multiple cells:

=SUM(IF('2009 Actual'!$C$3:$C$2063=$A6,IF('2009
Actual'!$P$3:$P$2063=$B6,'2009 Actual'!Q$3:Q$2063,0),0))

For two sets of these formulas I have an N/A result, but I know for a fact
that I should get a value. For the other four sets I have a value as
expected. I also have similar setups on four spreadsheets which are mirror
images but are different business units, unfortunately I can't be too
specific as it's confidential data. I've tried using formula auditing and
error checking but they didn't tell me anything! I noticed when I tried to
re-write the formula from scratch using the wizard it complained that the
formula was too large though?

Any help appreciated, I can give more detail about the formulas if needed
but I don't know what anyone will need to know to answer!!!

Thanks
Pat