While ColReorder works great with scrolling in DataTables (and thus FixedColumns), it also presents an additional option called 'iFixedColumns' which allows you to not let the user reorder certain columns (specific the number given, counting left to right). So in the case of FixedColumns this is useful because you typically won't want to let your fixed column be reordered. This is shown below in the FixedColumns index column example.
DataTables
$(document).ready( function () {
var oTable = $('#example').dataTable( {
"sDom": 'Rlfrtip',
"sScrollX": "100%",
"sScrollXInner": "150%",
"bScrollCollapse": true,
"fnDrawCallback": function ( oSettings ) {
/* Need to redo the counters if filtered or sorted */
if ( oSettings.bSorted || oSettings.bFiltered ) {
for ( var i=0, iLen=oSettings.aiDisplay.length ; i<iLen ; i++ ) {
$('td:eq(0)', oSettings.aoData[ oSettings.aiDisplay[i] ].nTr ).html( i+1 );
}
}
},
"aoColumnDefs": [
{ "bSortable": false, "sClass": "index", "aTargets": [ 0 ] }
],
"aaSorting": [[ 1, 'asc' ]],
"oColReorder": {
"iFixedColumns": 1
}
} );
new FixedColumns( oTable );
} );