this seems to be a wild hack, but as a matter of fact kio crashes when a kfile plugin provides 2 mimetypes (hover a jpg in trash:/ in KDE 3 and you will see 2 "servicetype trash not found" and 2 "servicetype system not found" and one ASSERT: count() == 1 in kfilemetainfo.cpp (975)

The problem is: this assert is fatal in KDE4, so I think this shouldn't do such wild hacks (what mimetype is "trash"?)