Thanks for your reply bmgoodman and jamileh! I would abandon upgrading my phone to ICS since I heard people who did the upgrade have  phone crashing, locking up and battery draining issues, and many of them even ask to go back to the gingerbread version. Like this post: http://forums.att.com/t5/Android-Discussion-and-Support/DON-T-gt-Samsung-Galaxy-S2-Android-4-0-Updat...