overridePendingTransition(0, 0); 을 onCreate 에 넣어보세요
http://developer.android.com/intl/ko/reference/android/app/Activity.html#overridePendingTransition(int, int)
http://stackoverflow.com/questions/15115404/is-there-a-way-to-disable-actionbars-show-hide-animation
위에 도움이 될 지 모르겠지만 참고해보세요.