What happens if you move the article to a temp name and then move it back?
I've tried that; it doesn't work, unfortunately. In fact, when I create other subpages for the same parent (e.g. [[User:WikiSysOp/Contact]]), it seems those too will just be pseudo-subpages - which is quite annoying... (While creating subpages for parents that didn't have pseudo-subpages before works just fine.)
-- F.