Conformance (SE2.2 beta #5)

Hi all,

I have an error message from SE about rejected conformance:

****** Fatal Error: Cannot pass `sorter' which is of type 
SB_H_ARRAY_SORTER[SB_FILE_LIST_ITEM]
into formal type SB_SORTER[SB_FILE_LIST_ITEM].
Line 35 column 25 in SB_SORTABLE_ITEM_CONTAINER 
(/data/eiffel/lib/gui/sb/no-BIT/widgets_mods/sb_sortable_item_container.e):
   set_items_sorter(sort: like items_sorter) is
                          ^
Line 101 column 21 in SB_FILE_LIST_DEF 
(/data/eiffel/lib/gui/sb/no-BIT/widgets_mods/sb_file_list_def.e):
         set_items_sorter(sorter)                       -- ???
                          ^

I have checked that SB_H_ARRAY_SORTER inherits (indirectly) from SB_SORTER, 
and the generic parameter (SB_FILE_LIST_ITEM) is effectively the same in 
each.

Can anyone explain, succinctly, whether there are any circumstances where the 
above conformance should fail?
-- 
Howard Thomson

--
"Only two things are infinite, the universe and human stupidity,
and I'm not sure about the former." -- Albert Einstein