>ControlSource = AliasName.Field
>Also, is every column and grid enabled? Yes.

I don't have more ideas. Check if there is anything extra in any method of the grid, what is its base class, is there any code in the form altering the grid's behavior and also if there is any shape/control close to the grid.

Also, are you using pageframe in that form? Can you also try copying that form without anything on it and just add the grid?