"Dalvik performs many of its own optimizations, and some of the optimizations performed by ProGuard are incompatible with Dalvik, so to avoid hard-to-figure-out

"Dalvik performs many of its own optimizations, and some of the optimizations performed by ProGuard are incompatible with Dalvik, so to avoid hard-to-figure-out bugs (and because the net performance gain is usually small), the default configuration turns off optimization." in http://tools.android.com/recent/proguardimprovements http://tools.android.com/recent/proguardimprovements