I have a broblem with UltraWebGrid.v8.2

I add new rows until ScrollBar show (by  igtbl_addNew(GridName, 0, true, true);) after click edit cell at column end then it happened matters:

Before Add new row:

After Add new row:

if use javascript them solve broblem is succesful.

what is? can i solve broblem by properties of grid?

Please help me.

Thank you very much!