Error when trying to reinstall current running activity

In my application I am reinstalling the same application after downl开发者_Python百科oading it from my server. I am assuming that I will get update of my app, now when installation begins I get dialogue box to replace current app and after it Application Not Installed exception comes. If I download anyother file, it downloads and installs but not reinstalling the same running app , what is the problem ??

log cat

08-05 11:47:44.745: INFO/ActivityManager(59): Displayed activity com.android.packageinstaller/.PackageInstallerActivity: 2699 ms (total 2699 ms)
08-05 11:47:46.665: INFO/AppSecurityPermissions(308): Ignoring unknown permission:android.permission.ACCESS_LOCATION
08-05 11:47:46.665: INFO/AppSecurityPermissions(308): Ignoring unknown permission:android.permission.ACCESS_ASSISTED_GPS
08-05 11:47:49.035: INFO/ActivityManager(59): Starting activity: Intent { dat=file:///mnt/sdcard/NCS.apk cmp=com.android.packageinstaller/.InstallAppProgress (has extras) }
08-05 11:47:49.215: WARN/InstallAppProgress(308): Replacing package:regency.cabs
08-05 11:47:49.656: INFO/ActivityManager(59): Displayed activity com.android.packageinstaller/.InstallAppProgress: 555 ms (total 555 ms)
(after  installation, I am exiting my app so user will re launch installed app)

You need to have both application signed with the same certificate, and also try increasing the 'android:versionCode'(in the AndroidManifest.xml)- it will notify the system that the application you are installing is newer. Can you post the Logcat log when trying to reinstall?