title: bad reference to MS.Practices.Data
body: <p>I have two project who reference to the same path of:</p>
  
  <pre><code>Microsoft.Practices.EnterpriseLibrary.Data.dll
  </code></pre>
  
  <p>I use </p>
  
  <pre><code>Database database = DatabaseFactory.CreateDatabase();
  </code></pre>
  
  <p>one project compiles OK and the other shows error:</p>
  
  <blockquote>
    <p>Error 1   The type
    'Microsoft.Practices.EnterpriseLibrary.Common.Instrumentation.IInstrumentationEventProvider'
    is defined in an assembly that is not referenced. You must add a
    reference to assembly 'Microsoft.Practices.EnterpriseLibrary.Common,
    Version=4.0.0.0, Culture=neutral, PublicKeyToken=null'.   &lt;---in file
    line.. -->    58  17  ControlPanel.Toolbar</p>
  </blockquote>
  
  <p>Why might I get this error?</p>