Hi, hope someone out there can help. I have a Samsung Galaxy S2 running android 2.3.3. The phone is not rooted and I've tried rebooting on several occasions. The problem is this: I make (or receive) a call using the speaker. Whilst the screen is lit the person on the other end can hear me and I can hear them. However, when the screen 'times out' and goes black I can still hear the other caller but they cannot hear me at all. If I then press the home button causing the screen to light up they can then hear me until the screen blacks out again. I am puzzled! Anyone got any ideas PLEASE? UPDATE: spoken with Samsung...it appears to be a software fault and is being repaired under warranty.