insertPages and page size

I know I'm missing something simple, but I don't see it.
 
I have a document that is 8.5in x 11in. I have another document that is 8.5x11in. When I do the following:
 
trustedInsPages = app.trustedFunction( function (cFilename, docptr)
{
app.beginPriv();
docptr.insertPages({
nPage: -1,
cPath: cFilename});
app.endPriv();
})
 
I end up with the 1st page being 8.5inx11in, but the page from the inserted document is 24 x 30.56 in.
  
Any ideas what I am doing wrong?