Create Columns at run time

[Tina]

if you place a datagrid on a form and then, in Property builder, check the
box saying Create Columns at run time. An then do a SQL Select into a
datatable, and then bind the datatable to the grid, the grid displays
correctly. BUT, the columns array is empty. The grid displays just fine.
There are cells and rows but no columns.

I want to make some of the columns non visible but I can't because there are
no columns.

Why is this?
Thanks,
Tina