title: wix major upgrade not installing all files
body: <p>I have a very simple WiX project (version 3.7) that installs somes files (a .NET program version 6.0.0.0). I'm ready to release a new version 6.0.1.0 using the MajorUpgrade functionality in WiX.</p>
  
  <p>I'm keeping the UpgradeCode the same in the Product element and I change the Version from 6.0.0.0 to 6.0.1.0</p>
  
  <pre><code>&lt;Product Id="*" Name="MyApp" Version="6.0.1.0" Manufacturer="Me" 
         UpgradeCode="$(var.TheUpgradeCodeGUID)"&gt;
  </code></pre>
  
  <p>On a machine with 6.0.0.0 installed, I run the new installer.</p>
  
  <p>The removal of the old version 6.0.0.0 runs ok (all installed files are being removed), but when the installer continues to install the new version, 2 files are missing: a 3rd party DLL and a 3rd party EXE (that haven't been changed) are not being reinstalled.</p>
  
  <pre><code>&lt;Component Id="AutomaticUpdaterWPF.dll" Guid="*"&gt;
          &lt;File Id="AutomaticUpdaterWPF.dll" Source="AutomaticUpdaterWPF.dll" KeyPath="yes" Checksum="yes" /&gt;
  &lt;/Component&gt;
  &lt;Component Id="wyUpdaterProgram" Guid="*"&gt;
          &lt;File Id="wyUpdaterProgram" Source="wyUpdate.exe" KeyPath="yes" Checksum="yes" /&gt;
  &lt;/Component&gt;
  </code></pre>
  
  <p>All other files in the &lt; ComponentGroup > (some modified, some unmodified incl. other 3rd party DLLs) are being installed correctly during the major upgrade.</p>
  
  <p>If I click on "repair" after the major upgrade, the 2 missing files re-appear.
  Also, if I install version 6.0.1.0 for the first time (no upgrade, but first installation on a clean machine), then those 2 files are installed directly and normally.
  (tested on several Windows machine (XP, 7 and 8)</p>
  
  <p>Anybody any suggestion what is wrong and how to fix it?</p>