Problem Creating Multivalue Parameters With An OLAP Cube

I am using a 2005 SSAS cube as a datasource for 2005 SSRS report with multivalue parameters. I use the design mode query builder to generate my MDX. I then add my parameter to my parameter field in the filters section. The name and value of the parameter in the dataset editor is as follows:

Name: FacilityFacilityNumber
Parameter: Parameters!FacilityFacilityNumber.Value

I then proceed to layout mode and then open up report parameters. I then check the multivalue box and select non-queried available values. I choose non-queried radio button because I want my asp page to be passing in the parameters, not a dropdown list.

The problem is that when I try and preview the report and I type in just one parameter I get the following:
"Query (1, 437) The restrictions imposed by the CONTRAINED flag in the STROSET function were violoated"

After looking through a couple of forums I found that adding the following Parameter value in the data tab and dataset editor would help me out a bit:
"[Facility].[Facility Number].&["+Parameters!FacilityFacilityNumber.Value+"]"

Ok so now (in layout mode) I type in one parameter and I get a report back, BUT when I try to type in a second or more parameter I get the same error as before:
"Query (1, 437) The restrictions imposed by the CONTRAINED flag in the STROSET function were violoated"


Here is the MDX query that I am using for this report:

SELECT NON EMPTY { [Measures].[Claim Count], [Measures].[Item Reasons Count], [Measures].[Charged Amount] } ON COLUMNS, NON EMPTY { ([Facility].[Facility Number].[Facility Number].ALLMEMBERS * [Claim Status Codes].[CLaim Status Code].[CLaim Status Code].ALLMEMBERS * [Claim Status Codes].[Claim Status Description].[Claim Status Description].ALLMEMBERS ) } DIMENSION PROPERTIES MEMBER_CAPTION, MEMBER_UNIQUE_NAME ON ROWS FROM ( SELECT ( STRTOSET(@FacilityFacilityNumber, CONSTRAINED) ) ON COLUMNS FROM [Claims Remittance]) CELL PROPERTIES VALUE, BACK_COLOR, FORE_COLOR, FORMATTED_VALUE, FORMAT_STRING, FONT_NAME, FONT_SIZE, FONT_FLAGS


Please, if anybody know's what I am doing wrong I would greatly appreciate it.......I have to have my report accept non-queried multivalued parameters. Thanks