title: "An assembly with the same simple name has already been imported" error without duplicate reference
body: <p>I'm getting the following error:</p>
  
  <blockquote>
    <p>error CS1704: An assembly with the same simple name
    'Interop.xxx.dll, Version=1.0.0.0, Culture=neutral,
    PublicKeyToken=null has already been imported. Try removing one of the
    references or sign them to enable side-by-side.</p>
  </blockquote>
  
  <p>Everything I've seen says that I am referencing two assemblies with the same name and I need to remove one of them.  However, I've checked and I'm only referencing it once.</p>
  
  <p>This also only happens when I'm using msbuild to build from the command line on my dev box.  If I build through Visual Studio or do a clean build on our CI server I don't see this error.</p>
  
  <p>I've tried completely removing all of my source and building from scratch to more closely resemble the build machine but no luck.</p>