i have the same issue using pivottable.
i'm trying to add an expression to a pivoit table using the following code:
ActiveDocument.GetSheetObject("chart2").AddExpression "count(distinct UnitItemID)"
but then get the "crossed" image on the pivot table.
If i edit the pivottable and simply click OK - the pivot works.
i guess additional properties needs to be set to the new expression, but i found no reference for how to do that.
Alex, have you found a solution for this issue ?