title: NoClassDefFoundError when starting android project
body: <p>After updating my Android SDK today none of my projects are working anymore.
  Whenever I try to run a project in the emulator I get a NoClassDefFoundError for the main class of the project.</p>
  
  <p>This class usually comes from another library project, that is linked with my main project (via right-click -> Properties -> Java Build Path -> Add...).</p>
  
  <p>PS: all my JARs are in a "libs" folder, so that shouldn't be a problem...</p>