getSelectedMember does not work on BEx Query Structure

Hi

Has anyone seen the following behaviour:

1. I have a BEx query
2. I created a design studio application that accesses the BEx query
3. The application displays a column chart. When you select a column, it 'jumps' to another tab that displays the detail in a table.
4. I used the following std. script

DS_DET.setFilter( "ZBCFLG005", CHART_1.getSelectedMember( 'ZBCFLG005' ) ); 

TABSTRIP_1.setSelectedTabIndex(1);

My issue is: when my Bex query uses a structure as a source for the chart, then getSelectedMember does not seem to provide the selected structure value (member) i.e. a simple structure filtered by characteristic ZBCFLG005.

However, when I change my BEx query by removing the structure and simply reporting the characteristic ZBCFLG005 in the rows, then getSelectedMember works i.e. provides the selected structure value (member).

How do I get Design Studio to read the member value from the BEx structure or is this a potential bug?

Thx