Multiselect on Time-Hierarchy with many-to-many relationship throws exception

The System is SQL-Server 2008 R2 Enterprise or Developer. I created a Testcube for this issue with a dimension "Time":

Dimension: Time; Hierarchy: Time; Levels: Year > Quarter > Month > Day

Measure Groups:

- FactSimple: Measure "DataSimple"; regular-relationship to Time.Month

- FactMulti: Measure "DataMulti"; many-to-many-relationship to Time.Month

this MDX results in "Internal Error: Unexpected Exception":

SELECT {[Measures].[DataMulti]} ON COLUMNS
FROM [TestCase]
WHERE ({[Time].[Time].[2013 Q1],[Time].[Time].[April 2013]})

but replace [Measure].[DataMulti] with [Measure].[DataSimple] and it works. The following WHERE-Statements do work for [DataMulti]:

--Working WHERE-Statements:
SELECT {[Measures].[DataMulti]} ON COLUMNS
FROM [TestCase]
WHERE ({[Time].[Time].[2013 Q1]})
--or
WHERE ({[Time].[Time].[April 2013]})
--or
WHERE ({[Time].[Time].[2013 Q1],[Time].[Time].[2013 Q2]})
--or
WHERE ({[Time].[Time].[Januar 2013] : [Time].[Time].[April 2013]})

Then I added a second Hierarchy to the Dimension Time:

Dimension: Time; Hierarchy: DownToMont; Levels: Year > Quarter > Month;

It uses the same Attributes as hierarchy "Time" and with this Hierarchy this works:

SELECT {[Measures].[DataMulti]} ON COLUMNS
FROM [TestCase]
WHERE ({[Time].[DownToMonth].[2013 Q1],[Time].[DownToMonth].[April 2013]})

I hope Microsoft is interested in this issue.