Horizontal scroll bar should appear when auto size columns mode is enabled and columns has minimum width that cause the total width of the columns to be more that the visible area width.
Just ran into this problem, using a re-sizable window and it needs to autofill when the user makes it bigger than the grid, but use horizontal scrolling when the user makes it smaller than the grid.
I'd also like to know when we can expect this to be fixed.
When are you thinking of implementing this feature? I really need it.