title: adb devices list empty ubuntu 12.04 s5830
body: <p>My problem is that adb devices does not detect my galaxy ace (s5830) using Ubuntu 12.04,
   I tried everything but still not working.
  Can help me where fault.
  I have installed oracle sdk 1.7, last android sdk and I have created the rule 51-android.rules with permissions a+r</p>