oAria is undefined

Hi,

I use DataTables version 1.9.4. I want that the initial sorting is made on the column 8.
oTable.fnSort( [ [8,'desc'] ] ) works well, but sends back an error in Javascript console of Firefox ( oAria is undefine ) and stops the continuation of the JavaScript.
For information : jquery.datatTbles.js line 4082: (aoColumns[i].asSorting[0]=="asc" ? oAria.sSortAscending : oAria.sSortDescending) )

DataTables debugger does not indicate the error

Regards,