As you might know you can place different controls for integer values on a form. E.g. Int64Edit for 64 bit integers or IntEdit for 32 bit values. Some time ago during developing I found that there might be an issue if you are having an Int 64 in a table and on a form control you have an IntEdit instead of an Int64Edit control.
In your database you will get different numbers compared to what you get within your grid. For example the number 214748367 might end up as 9824293160484863.
Please keep in mind that the form control type needs to match the data type in the table.