header and footer classes change recently?

I'm upgrading to the 1.9.1 and as a side effect I am seeing that the two divs under the dataTables_wrapper DIV and surrounding the table itself doesn't have anymore the "fg-toolbar ui-toolbar ui-widget-header ui-corner-tl ui-corner-tr ui-helper-clearfix" as classes, but an empty classes.
Those are the header and footer with the filtering and pagination options

Is that something which changed recently and that I have missed or did I mess up something in the upgrade?

Thanks
jean