Have you tried moving the main article (rather than the subpage) somewhere else as well? I'm not quite sure what order to move things in, but you might be able to trick it with some combination.
I've tried moving things around a little (thus probably creating quite a mess of empty/redirecting nonsense pages), but to no avail. However, the [[User:WikiSysOp]] page was empty before - i.e. only [[User:WikiSysOp/ToDo]] existed. After creating some content in [[User:WikiSysOp]], [[User:WikiSysOp/ToDo]] suddenly had the breadcrumb - so at least that worked...
-- F.