T-Mobile Samsung Galaxy S2 (T989) Lag, Freezing, Unresponsive after ICS Update? Try this.

You should try wiping your cache partions.

Take out the battery

Put it back in

Hold Volume up + Volume down + Power until you feel it vibrate and see the "SAMSUNG"

Let go off power but keep holding volume buttons

this boots you into 3e recovery

use volume down to scroll to wipe cache partions

hit home to select

and then scroll back up to reboot and then hit home

hope it helps 

From: http://support.t-mobile.com/thread/27442?start=0&tstart=0

Thanks toindian9990