Since the last up date (4.4.2) to my Samsung Galaxy Tab 3 10.1, it's been unstable. At times it seems to go into sleep mode, I see the Samsung logo appear with the stupid spinning blue oval, then my login screen or black screen; usually when using Facebook, it seems to be the most problematic but it happens with other apps as well. Never had these issues with my Asus (to bad I dropped it.) Guess we'll have to hurry up and wait for Samsung to fix what they broke. Thank you Samsung!