title: Converting from EmguCV 3.1 to 3.3 causes code to hang
body: <p>In EmguCV 3.1.X (installed from Nuget) with the non-commercial license I had this code, which I got from  <a href="https://stackoverflow.com/questions/32255440/how-can-i-get-and-set-pixel-values-of-an-emgucv-mat-image">here</a> and which worked fine:</p>
  
  <pre><code>    public static dynamic GetValue(this UMat mat, int row, int col)
      {
          var value = CreateElement(mat.Depth);
          Marshal.Copy(mat.ToMat(AccessType.Read).DataPointer + (row * mat.Cols + col) * mat.ElementSize, value, 0, 1);
          return value[0];
      }
  </code></pre>
  
  <p>I now want to switch to the commercial version of EmguCV 3.3.X (installed from Nuget) and therefore had to change this code into:</p>
  
  <pre><code>    public static dynamic GetValue(this UMat mat, int row, int col)
      {
          var value = CreateElement(mat.Depth);
          Marshal.Copy(mat.GetMat(AccessType.Read).DataPointer + (row * mat.Cols + col) * mat.ElementSize, value, 0, 1);
          return value[0];
      }
  </code></pre>
  
  <p>For no apparent reason, this code hangs without exception or anything on the line:
  <code>Marshal.Copy(mat.GetMat(AccessType.Read).DataPointer + (row * mat.Cols + col) * mat.ElementSize, value, 0, 1);</code></p>
  
  <p>Am I doing something wrong or could this be bug in EmguCV?</p>