I have a curved shower rod ( http://tinyurl.com/2pfbw7 ) held up with
four wall plugs like http://tinyurl.com/2h8z87 . Don't ask me how but
one and only one of those plugs seems to be pulling out. (I know it's
easy to torque the rod but how can only *one* of the anchors pull
out?) In any event, I need to repair this before it comes completely
out. I
can't move the rod so I've got to repair the hole or put another
fastener in the same place.

I've considered taking the whole thing down, removing the lose anchor,
filling the hole with spackle or paster of paris, and starting over.
And I've considered using a molly or something that, I hope, would
open behind the back paper of the plasterboard and distribute the
stress of the rod over a large area. Any recommendations?

Chris