True Grid fails to drop ValueItems list

We have repeatedly had the following problem on True Grid 7.0 in VB6.

We will try to get a particular column to be a drop list. We will fill up the ValueItems property. But the list refuses to drop.

We have identified 2 different causes for this problem.

1. The field in the drop list wasn't in the query loading the (bound) grid.
2. The Presentation property was not set to Combo Box.

Hope this helps somebody out there. 1