bhidden doesn't keep document hidden when using openDoc

When I open a doc:

var otherDoc = app.openDoc({

     cPath: "myDoc.pdf",

     bhidden: true,

     oDoc: this

});

My understanding was that "bhidden" should make the doc you're opening stay hidden.  When I do this, everything works fine, but the document opens in plain sight, and stays there until I close it (either manually or using closeDoc).  What am I doing wrong?

Thanks!