GOS cl_gos_manager attachment list

Hello,

I have added the GOS object to my transaction by the following ABAP code:

MODULE status_0100 OUTPUT.

SET PF-STATUS 'STAT_0100'.

SET TITLEBAR 'START'.

IF lo_atb_gos is initial.

ls_object-objtype = 'BUS2105'.

ls_object-objkey = ''.

create OBJECT lo_atb_gos

exporting is_object = ls_object

ip_no_instance = 'X'

IP_NO_COMMIT = 'R'

exceptions

others = 1.

ELSE.

CALL METHOD LO_ATB_GOS->GET_CONTEXT_MENU

.

ENDIF.

ENDMODULE. " STATUS_0100 OUTPUT

Buth when I add an attachment with the men "Create  Create attachment list" I'm able to add documents so far I could see. If I return to the GOS object the menu option "Attachment list" is not enabled.

Could any one explain why?

Many thanks,

Richard Meijn