title: Run test vs. Debug test = different results
body: <p>We have some unit tests that check the result of the solution of linear system of equation, comparing floating point numbers with a delta.</p>
  
  <p>Trying to adjust the delta, I noticed that the same number changes slightly between Visual Studio <code>Run test</code> and <code>Debug test</code> modes.</p>
  
  <p>Why does this happen? When I debug a test the <code>#if DEBUG</code> sections are disabled, therefore the executed code should be the same.</p>
  
  <p>Thanks.</p>