I haven't been able to see any real difference between the form that works and the 3 which do not. They each have one grid and a set of text buttons. No other objects on the form. Each grid is populated from one free table. It's very simple.

The users have to manipulate this data to some degree. They are scheduling deliveries of Roof Tile, so it's being used like a spreadsheet. We used to use a spreadsheet, but that's too cumbersome now. The company is growing. They need to work within the table with no intermediate processes.

Bottom line -- Form with one grid, one button set and one free table. This should be a no-brainer.