Hello there!
I have two worksheets in a notebook:
One is the data source, the other is a lot of "sumproduct" formulas
tabulating totals.

Everything seemed to be working fine, then...
One of the rows in the tabulating worksheet started outputting zeros instead
of the totals it was giving me before.

Any idea what is happening?
(Below I state the problem in a different way:)

My tabulating worksheet looks like this (Column 'A' is labels, B and C
columns have formulas):
A B C
--|---------------------
1| P1 F1a F2a
2| P2 F1b F2b
3| P3 F1c F2c
4| P4 F1d F2d


This shows that the column B (sumproduct) formulas are exactly the same for
every 'P' except for one condition (i.e. factor).
Also, column C (sumproduct) formulas are exactly the same, except for one
condition/factor.
The factor (a, b, c, d....) that distinguishes P1's F1 formula from P2's F1
formula is the same factor that distinguishes P1's F2 formula from P2's F2
formula.

I did a sort on a section of data (that corresponding to P2) on the source
data worksheet, and upon calculating, all formulas in that row outputted "0".

I have tried reentering them, creating a new column, checked the source
data... I can't figure it out. It seems specifically to have to do with the
factor/condition in those formulas, although it was working fine previously.

Any leads are greatly appreciated!

Thanks!
--Rachel.