title: VS2010 project -- unresolved references (where HintPath property missing)
body: <p>We are in the process of changing our build computer to a new one and at the same time to Visual Studio 2010. We have around 500 different small components, each one an own <em>csproj</em> file, all of them having references to assemblies in a "\Framework\bin\" directory.</p>
  
  <p>After getting the whole source code and starting compiling our projects, we've ran into a problem: many references cannot be resolved, but not all of them, and not always the same references on different projects. The problem seems to be linked to the <strong>HintPath</strong> attribute of the <em>csproj</em> files.</p>
  
  <p>Specifically, here's an example for a reference that <strong>can</strong> be resolved:</p>
  
  <pre><code>&lt;Reference Include="AIS.Common, Version=8.1.0.1, Culture=neutral, processorArchitecture=MSIL"&gt;
    &lt;SpecificVersion&gt;False&lt;/SpecificVersion&gt;
    &lt;HintPath&gt;..\..\..\Framework\Bin\AIS.Common.dll&lt;/HintPath&gt;
  &lt;/Reference&gt;
  </code></pre>
  
  <p>And here's one that <strong>can't</strong>:</p>
  
  <pre><code>&lt;Reference Include="AIS.ControlLib, Version=9.1.0.1, Culture=neutral, processorArchitecture=MSIL"&gt;
    &lt;SpecificVersion&gt;False&lt;/SpecificVersion&gt;
  &lt;/Reference&gt;
  </code></pre>
  
  <p>Strangely, the properties of the two references in Visual Studio are exactly the same (except for their Name and Identities, of course). So it seems that <strong>HintPath</strong> is auto-generated, but why only on some references?</p>
  
  <p>We suspect the problem could arise from using different version of Visual Studio (of the 500+ projects, some are in VS2005, others in VS2008, others still in VS2010), but we could not narrow the behaviour down to something logical.</p>
  
  <p>Is there any way to compile our projects without having to resort to manually reattach the unresolved references?</p>