How to display all tablix columns, including zero

I am developing an SSRS 2008 tablix. The problem that I have though is that I need to display all 12 months of the year. Currently, it only displays columns with values > 0. Even though I entered this expression for that field:

=IIF(Sum(Fields!NumActionPlanRemainOverdue.Value)=0, 0, Sum(Fields!NumActionPlanRemainOverdue.Value))

What else can I do?开发者_开发百科

---

From what I know, a Tablix does not hide non-positive rows. Can you verify that the dataset is returning a row for every month?

Some additional considerations are:

• Are you showing the data in a Tablix or a chart?
• What data type is the month column?