cl_salv_table: View could not be changed to: &VEXCEL

    TYPES: BEGIN OF tp_ty,             trkorr   TYPE trkorr,             as4text  TYPE as4text,             toc      TYPE trkorr,             importd  TYPE d,             importt  TYPE t,             impcount TYPE i,           END OF tp_ty.    DATA: t_tp  TYPE STANDARD TABLE OF tp_ty WITH NON-UNIQUE KEY table_line,          r_alv TYPE REF TO cl_salv_table.
...    TRY.        cl_salv_table=>factory( IMPORTING r_salv_table = me->r_alv                                CHANGING  t_table      = me->t_tp ).      CATCH cx_salv_msg.    ENDTRY.    adjust_column_text( ).    lr_functions = me->r_alv->get_functions( ).    lr_functions->set_all( abap_true ).    me->r_alv->display( ).

When the alv is displayed, I get the Excel function button.  But when I press it, I get message View could not be changed to: &VEXCEL

Something to do with the structure of t_tp perhaps?

Thanks,

matt