Calculation difference between Excel 2K and 2003
 

In 2000, after formulas have been calculated, copying / pasting values is
quick. Excel doesn't recalculate..it just pastes the non-dirty results.

In 2003, after formulas have been recalculated, Excel seems to recalculate
everything from scratch and it takes twice as long to copy/paste values as
in 2000.

Is this normal? Basically, calculation in 2003 is agonizingly slow. Why the
change in calculation approaches?

Thanks.