Cross join in Named set

How to use cross join in Named Set of a Cube.

I have wriiten a expression for TopCount with CrossJoin like:

1) TOPCOUNT(CROSSJOIN( [DimScale].[Source].Children, [DimScale].[ID].Children ), 5, [Measures].[Tickets])

2) And also written in script command like :

  CREATE DYNAMIC SET CURRENTCUBE.[Top5Source]
       AS TopCount
     ( NONEMPTYCROSSJOIN(
 [DimScale].[Source].[Source].Members,
[DimScale].[ID].[ID].Members ), 25,
[Measures].[Tickets] )

If I use the above expresion in SSMS(MDX), it works fine and I see the results. But when placing this expreesions in NamedSet of Cube, none of the namedset itslef are visible after processing the Cube.

Can anyone let me know how to use Cross joins in Named Set, or is there any mistake in my exprssion.

Thanks,