MDX help with a scope statement

[eo]

Hi,

I have a cube, and would like to sum measures where two dimension attributes intersect.
The first dimension is Claim and the second is LossDate. The hierarchical structure for each is...

Claim:

Dimension - [Claim]
Hierarchy - [ClaimNo]
Attribute - [ClaimNumber]

LossDate:

Dimension - [DateLoss]
Hierarchy - [DateLoss]
Attribute - [YearNo]

And herewith the section in the MDX code:

SCOPE([Claim].[ClaimNo].[ClaimNumber],[DateLoss].[DateLoss].[YearNo]);

    [MEASURES].[GrsClaimIncurred] = 
        //Sum(Descendants([Claim].[ClaimNo].CurrentMember)
        Sum(Descendants([Claim].[ClaimNo].CurrentMember,[DateLoss].[DateLoss].[YearNo])
            ,[MEASURES].[GrsClaimIncurredTotal]
            );

END SCOPE;

I am expecting to seethe measure GrsClaimIncurredTotal summed when I slice by both those hierarchical structures. It does not seem to deliver the correct result, and I think there is a problem with my scope.

I am ultimately trying to do further calculations that applies at this specific scope, and no lower (for example at Claim Number transactions or Month levels, so are trying to enforce this with the scope...

EO
Hertfordshire, England