Unable to get value of the property 'getItems': object is null or undefined ISC_Grid

Getting the following JS error on subsequent fetchData() on a ListGrid. It is fine on the first call, but subsequent calls throws this error.

When does this getItems() function is called?

Also this happens only when the ListGrid has some editable columns.

SCRIPT5007: Unable to get value of the property 'getItems': object is null or undefined
ISC_Grids.js?isc_version=v9.0p_2013-11-03.js, line 1264 character 338

In, Chrome it says:

Uncaught TypeError: Cannot read property 'getItems' of null

Smartclient Version - 9.0 Power Edition
Browser - IE 9, Chrome