Just a question: Would it help if you first booted X, and from there ran init 2? (I wonder if that Xauthority stuff has ever been really sane.)
Could seem like a bug to me, if the behavior is reproducible, in particular if it is fixed by bringing X up and down.
BTW, if you do this same mounting every time, you might put it in rc.local - that's what I ususally do.