I read it here ActionBar with support library and Fragments overlay content I am sure it will help you :
For pre ICS devices you must use:
R.id.action_bar_activity_content
instead of
android.R.id.content
R.id.action_bar_activity_content is a new id used in layout for displaying app content, it would appear that it replace android.R.id.content when you use support v7 appcompat ActionBarActivity.
You can use this code to retrieve the correct id of the activity content :
public static int getContentViewCompat() { return Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH ? android.R.id.content : R.id.action_bar_activity_content; }