Sum of values including Null in Pivot Table

[#1]

I have a Pivot Table with Null fields ( - ). I would like to return the sum for one year. The sum includes some null values.

I have tried so far with

Sum({<[Year]='2011'>}[Revenue]))

and this returns 0 or None, so that there is some mishandling of the nulls apparently.

[Gysbert_Wassenaar]

Try Sum({<[Year]={'2011'}>}[Revenue])

[#3]

This does not make it

[Gysbert_Wassenaar]

Yes it does. It works perfectly here.