cell values not updated

The cell values are not updated in dbase when some repeated values are entered .

For ex if in Amount column i enter

first time 300

its get updated

second time 400

its get updated

third time 300

its is not updated and it shows 400.

Problem can’t be reconstructed locally. The grid doesn’t preserve original value of cell, so each next change must trigger data update event.
Which version of dhtmlxgrid are you using ?