title: Proguard: there were 210 duplicate class definitions?
body: <p>Eclipse shows warnings below, it seems it has something with proguard. But my project can be signed in other computer, and I did signed it before! what's wrong? how to fix it?</p>
  
  <p>Note: there were 210 duplicate class definitions.
  You should check if you need to specify additional program jars.
  Warning: can't write resource [META-INF/MANIFEST.MF] (Duplicate zip entry [android-support-v4.jar:META-INF/MANIFEST.MF])
  ...</p>