Using fnCreatedRow to add detail rows (working, but not)

I have the following simple piece of code:

"fnCreatedRow": function( nRow, aData, iDataIndex ) {
     $('.draft-claims tbody tr:eq('+iDataIndex+')').after($("<tr class='odd'><td colspan='7'> New row here </td></tr>"));
}

When stepping through the code I can see that it works, however as soon as the function is finished the row is removed. I assume there is some last piece of initialisation code that removes this row?