Broken IF formula in 09?

Question

In Numbers 08, I used the following IF formula to return an empty cell if there is no data to sum:
=IF(COUNT(E22:E38)>0,SUM(E22:E38),"")
I do not want it to show zero if there are no numbers to sum. Just be blank.
In Numbers 09, that formula appears to work correctly, but when I try to SUM a cell which contains that empty cell, I get an error which says, The operator "+" expects a number, date or duration but found "."
Any clue what's wrong? It worked fine in Numbers 08.

Answer 1

I don't want to be rude but, may you look at existing threads before posting?
This question was already responded several times.
There is a change between Numbers '08 and Numbers '09
In Numbers '08, a cell containing an empty string was accepted as a zero in arithmetic operations.
In Numbers '09, it is treated as a string. As it is theorically correct, and as it is not documented, we don't know if it's a bug or a deliberate choice.
The workaround was already given:
use SUM() in lieu of the + operator.
For other operations, we must use the IF() function
=IF(C="",0,C)-IF(B="",0,B)
=SUM(C,-B) reject an empty string in B (the operator "-" requires a number) but accepts it in C
=IF(C="",0,C)*IF(B="",0,B)
or, if we are in row 10
=PRODUCT(C10,B10)
=IF(C="",0,C)/IF(B="",0,B) (which of course will return an error if B is nil)
QUOTIENT() rejects an empty string as dividend (of course it rejects also it as divisor).
Yvan KOENIG (from FRANCE dimanche 11 janvier 2009 17:15:14)