After I set android:targetSdkVersion to 15, application doest work in 1.6 emulator.
It throws java.lang.VerifyError.
Edit:
The app is crashing because I’m calling invalidateOptionsMenu, which came in API 11. Now even I check before calling it (if (VERSION.SDK_INT >= 11)). It still throws same error.
Nice trick in this answer. Brilliant. Thanks everyone.