Hey, So on the 27th I picked up a Galaxy S4. Today I started using it more as my service changed over. This is where the problems began. Firstly, if I lock my screen, then hit the button again to unlock it, there is no "YES OPTUS" down the bottom, and it wont let me swipe, as if the screen was completely unresponsive (well it is). If i hold down the physical power button while it is in this "glitched" state. The menu will show up, however i cannot select anything on it (still an unresponsive screen) Also, when making a call, i'll call the number, put the phone to my ear, and if i want to hang up while its ringing, i remove it from my ear, and hit hang up.. right? Nope - It once again goes unresponsive for an indefinite amount of time - No longer than two minutes. I called Samsung Technical Support regarding this issue, and took out my battery and sim. This did not fix the problem. I was advised by samsung that optus should give me another phone upon returning my current one. I want to know if there are any more steps i can take, if anyone else is experiencing this. (I'm also very worried about the fact they may not be any in stock at my local store) Please help me in diagnosing this problem and finding a fix, thanks!