Empty Columns Won't Display in Matrix With MDX Query

I've scoured the boards for an answer to this and haven't been able to find an anwser. I know I've solved this once before but for the life of me cannot remember how!

I have a report whose results are derived from an MDX query, which is below:

SELECT
    {[Measures].[AR INV AMOUNT]} ON COLUMNS
 ,NON EMPTY
    {
        [DIM PROJECT].[Client].[Client].ALLMEMBERS*
        [DIM AR INVOICE].[Invoice Date].[Invoice Date].ALLMEMBERS*
        [DIM AR INVOICE].[POSTPERIOD].[POSTPERIOD].ALLMEMBERS*
        [DIM AR INVOICE].[Invoice Number].[Invoice Number].ALLMEMBERS*
        [DIM INV AGE RANGE].[INV RANGE ID].[INV RANGE ID].ALLMEMBERS*
        [DIM INV AGE RANGE].[Invoice Age Range].[Invoice Age Range].ALLMEMBERS
    }
  DIMENSION PROPERTIES 
    MEMBER_CAPTION
   ,MEMBER_UNIQUE_NAME
   ON ROWS
FROM 
(
  SELECT 
      StrToMember
      (@FromTimeYearMonth
       ,CONSTRAINED
      )
    : 
      StrToMember
      (@ToTimeYearMonth
       ,CONSTRAINED
      ) ON COLUMNS
  FROM 
  (
    SELECT 
      StrToSet
      (@DIMPROJECTClient
       ,CONSTRAINED
      ) ON COLUMNS
    FROM [ACCOUNTING]
  )
)
CELL PROPERTIES 
  VALUE
 ,BACK_COLOR
 ,FORE_COLOR
 ,FORMATTED_VALUE
 ,FORMAT_STRING
 ,FONT_NAME
 ,FONT_SIZE
 ,FONT_FLAGS;

This is a screenshot of the current results/output:

There should be four other ranges: 0 to 30, 31 to 60, 61 to 90, 91 to 120. Even if there are no invoices that fall under one of those categories, all five range hedings should appear in the report

In the report, I have a column group on INV_AGE_RANGE. There are five possible values for this dimension member. When running the report and there are no values for one of the ranges, that column does not appear. I used an IIF expression in the value field so if there is nothing, the value should be set to 0.

Not sure how to get this to display properly.

I guess long tory short: how do you display columnss in a matrix even if no value in field.

Thanks!!

A. M. Robinson