New Post: datagrid sorting problem

Is there a way to make a datagrid ALWAYS sort by the group selections first when those group selections are being made at runtime by the user.
I basically need to be able to sort by any column but I don't want my groups jumping all over the screen each time i implement a sort. I want sorting to be done within groups.
Any ideas?

It would also be useful to me if when you perform a sort change groups stay in the state they are in (expanded or not) and do not have to all expand or close.