Exception when I run my application from Eclipse

Try adding one more thing in Manifest file, I am sure you have already tried..

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="[my package]" 
    android:versionCode="1" 
    android:versionName="1.0"
    android:sharedUserId="com.mj.app" > 

It seems like in your project you have multiple PACKAGES, like com.package.p1 , com.package.p2 ,com.package.p3..

And while starting you are in p1 and then moves on to p2 - p3…
and at that time you try to run it again..so the Android gives you error.