How to use Colvis with fnFooterCallback?

Hello to all,

I try to use fnFooterCallback in order to calculate the sum of some columns. It is ok and pretty cool! But unfortunalty, my Javascript fails when I want to add the ColVis function on my table.

My HTML:

<table id="mydatatable">
<thead>
<tr><th>Part number</th><th>Desc 1</th><th>Desc 2</th><th>Quantity</th><th>Weight</th><th>Height</th><th>Misc</th></tr>
</thead>
<tbody>
<tr><td>201-1704</td><td>desc 1</td><td>desc 2</td><td>1</td><td>6</td><td>14</td><td>misc</td></tr>
<tr><td>6Y-4898</td><td>desc 1</td><td>desc 2</td><td>2</td><td>1</td><td>6</td><td>misc</td></tr>
<tr><td>6Y-5685</td><td>desc 1</td><td>desc 2</td><td>3</td><td>2</td><td>11</td><td>misc</td></tr>
<tr><td>4I-7472</td><td>desc 1</td><td>desc 2</td><td>4</td><td>6</td><td>12</td><td>misc</td></tr>
<tr><td>124-3296</td><td>desc 1</td><td>desc 2</td><td>5</td><td>6</td><td>13</td><td>misc</td></tr>
<tr><td>141-9655</td><td>desc 1</td><td>desc 2</td><td>6</td><td>2</td><td>14</td><td>misc</td></tr>
<tr><td>166-3729</td><td>desc 1</td><td>desc 2</td><td>7</td><td>3</td><td>6</td><td>misc</td></tr>
<tr><td>207-3658</td><td>desc 1</td><td>desc 2</td><td>8</td><td>6</td><td>6</td><td>misc</td></tr>
<tr><td>255-8095</td><td>desc 1</td><td>desc 2</td><td>9</td><td>6</td><td>4</td><td>misc</td></tr>
<tr><td>125-4403</td><td>desc 1</td><td>desc 2</td><td>10</td><td>3</td><td>4</td><td>misc</td></tr>
</tbody>
<tfoot>
<tr><th>Total</th><th></th><th></th><th></th><th></th><th></th><th></th></tr>
</tfoot>
</table>

My JS:

$("#mydatatable").dataTable({
"aaSorting": [],
"bSort": true,
"bPaginate": true,
"bAutoWidth": false,
"sDom": 'C<"clear">lfrtip',
"oColVis": {"buttonText": "Hide", "aiExclude": [0, 1, 2]},
"fnFooterCallback": function(nRow, aaData, iStart, iEnd, aiDisplay) {
	var arraytotaux = [];
	arraytotaux[3] = 0;
	arraytotaux[4] = 0;
	arraytotaux[5] = 0;
	for (var i = 0; i < aiDisplay.length; i++) {
	arraytotaux[3] += aaData[aiDisplay[i]][3] * 1;
	arraytotaux[4] += aaData[aiDisplay[i]][4] * 1;
	arraytotaux[5] += aaData[aiDisplay[i]][5] * 1;
	}
	var nCells = nRow.getElementsByTagName("th");
	nCells[3].innerHTML = arraytotaux[3];
	nCells[4].innerHTML = arraytotaux[4];
	nCells[5].innerHTML = arraytotaux[5];
}
})

Problem starts when I try to hide or show columns, with this kind of messages:

TypeError: nCells[5] is undefined
nCells[5].innerHTML = arraytotaux[5];

Could you please help?

Thanks.

Regards.

Kyvu