Hidden columns dont get updated.

Hi I have created an expand/collapse feature for my datatable. So when I collapse I hide few columns using aTable.fnSetColumnVis( 2, false);

My problem is that in the collapsed form these columns dont get updated when I call -
aTable.fnUpdate([
aData[colArr[0].sName],
aData[colArr[1].sName],
aData[colArr[2].sName],
aData[colArr[3].sName],
aData[colArr[4].sName]], rowIdx[0], 0);

Is there anything that I can do to resolve this.

Thanks in advance for your help.