COPY EXCEL PDF buttons appear at bottom

When i click the "Save" button COPY EXCEL PDF buttons appear at bottom of screen though all the options work as expected but why are they appearing at bottom of table when they should have been appearing below "Save" button.Here is the screen shot for same . http://postimg.org/image/6hz11zytx/ Here is the code

"tableTools": {
        "sRowSelect": "os",
        "sSwfPath": "../../../TableTools/swf/copy_csv_xls_pdf.swf",
        "aButtons": [
            { "sExtends": "editor_create", "editor": editor },
            { "sExtends": "editor_edit",   "editor": editor },
            { "sExtends": "editor_remove", "editor": editor },
            {
                sExtends: "collection",
                sButtonText: "Save",
                sButtonClass: "save-collection",
                aButtons: [ 'copy', 'xls', 'pdf' ]
            },
            'print'
        ]
    }