Dialog Service behind content

Hi,

i am trying to implement a dialog service which pops up when a user double clicks on a datagrid row, this works fine and i have done this in the past. however, in this page, i am using tabs and i call the Dialogservice.openasync from the code and when this is called, the dialog is behind any datagrids i have not in front of it as it usually is. i have done this way many times to get the desired result, but this time i cannot see why the content is not at the front?

anyone have any ideas?

cheers