I got this phone he almost a week ago and I have already experienced some minor glitches. Sometimes it's really slow to react to touch. Sometimes things happen that I nevermeant to touch. Sometimes the gallery lags as well. Worst of all, sometimes when I Open the lock screen using either the home button or the side one, a couple of grey lines show up first before the lock screen like the screen or the LCD is broken. Should I have thus replaced? Sometimes the phone works perfectly. Or am I being too paranoid?