datagrid.getColumnAt(x).width not working properly ?? any clue?

Hi,

I want to dynamically change the width of a particular column (while other other columns will have their standard width (120 in my case)) in datagird using this line:

datagrid.getColumnAt(cellClickedColumn).width=newTopBarWidth;

However, this is changing all column sizes and distributing the size non-uniformly across the columns...

any clue, how to resolve this?

i've already set datagrid.HorizontalScrollPolicy="off";