title: Eclipse CDT automatically pulling in /usr/include/boost when not in include paths
body: <p>I am trying to build a project with PCL. I am using pcl, vtk-5.8 and eigen3. I am also using boost. </p>
  
  <p>In /usr/include boost 1.46 is there by default and I have built my own version of boost 1.5.1. When adding the path to boost 1.5.1 include dir to the include path (in properties->build->settings) I get errors on launch as my app is being compiled against the files in /usr/include/boost and not the 1.5.1 version. So when I don't include my boost 1.5.1 version everything runs fine.</p>
  
  <p>My question is, how/why is eclipse finding /usr/include as an include path (this has not been explicitly added) and how can I stop it doing this?</p>