unexpected layout in row editor

> Dear All,
>
> My pivot version is 1.5.1.
>
> My program would like use previewSaveChanges to check the amount is correct
> or not before save the row.
> If correct return Vote.APPROVE,otherwise return Vote.deny and let user
> re-input some wrong fileds.
> But when I drop the scroll bar,unexpected screen shown.
> (my production program has many fileds,So we need the scroll bar)
> So could you help to investigate the solution?
> many thanks.
>
> unexpected screen
>
> (Embedded image moved to file: pic02995.gif)
>
> Normal Screen.
> (Embedded image moved to file: pic11942.gif)
>
> Source code:
> (See attached file: RowEditorDemo.json)(See attached file:
> CurrencyValidator.java)(See attached file: CustomTableRow.java)(See
> attached file: demo.wtkx)(See attached file: ExpenseType.java)(See attached
> file: RowEditorDemo.java)