@plog - I believe it would display differently if not enabled. It would look more "grayed out" in that case.
@VSolano - can you open that form in design view, select that box, and take screen shots of the properties? One of the data or format properties is probably set wrong. Just not sure which one. There is also this question: Can you enter data or see data in that text box to the left of the four command buttons? The form's AllowEdit might be set incorrectly, which would have the indicated effect - particularly if you can't do anything with the text box either.