Posting the actual exception will help...
It seems the texture 'launcher' is already loaded sometimes when started again:
03-17 21:54:11.705: E/AndroidRuntime(5916): FATAL EXCEPTION: GLThread 70751
03-17 21:54:11.705: E/AndroidRuntime(5916): java.lang.RuntimeException: [ 1363553651668 ] - ERROR: A texture with the name 'launcher' has been declared twice!
03-17 21:54:11.705: E/AndroidRuntime(5916): at com.threed.jpct.Logger.log(Logger.java:189)
03-17 21:54:11.705: E/AndroidRuntime(5916): at com.threed.jpct.TextureManager.addTexture(TextureManager.java:138)
03-17 21:54:11.705: E/AndroidRuntime(5916): at com.example.tanktest.Tanktest$MyRenderer.onSurfaceChanged(Tanktest.java:265)
03-17 21:54:11.705: E/AndroidRuntime(5916): at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1505)
03-17 21:54:11.705: E/AndroidRuntime(5916): at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1240)
03-17 21:54:11.755: E/android.os.Debug(2267): !@Dumpstate > dumpstate -k -t -z -d -o /data/log/dumpstate_app_error