Datagrid Master Detail listener error when detail content is another datagrid

[aswzen]

I have a master detail datagrid table..look like this picture



and when i hover,click, or select the datagrid inside master detail especially item no.1, the item no.1 in master datagrid will be selected too..
why this is happened? just look at pic below



fyi: i don't want to use nested subgrid..or subgrid..

thanks in advance...