Could you post an example of one of the formulae giving rise to this
problem?

Pete

On Jul 26, 7:50 pm, HydrotechChris
wrote:
I have recently begun to experience random problems with conditional IF
formulas not returning zero but a very very tiny negative number, which
causes wrong results in other cells which rely on a zero value from the IF
formula to calculate correctly. In a reservoir routing speadsheet with say
2000 rows of calculations and 1000 that should be zero, two are not, but
tracing them can take hours expanding every cell display to 15 or more
decimal places to find which are not zero. I have never had this problem
before. It started in Office XP, but today I upgraded to Office 2003 and the
error is still there. Using ROUND everywhere is a work around but
significantly increases the size of the spreadsheet. Does anyone know the
cause and solution?
--
Hydrotechchris