I started to notice the red x when I got the last Jellybean update 4.2.2 for my Samsung Galaxy Tab 2 7.0 inch. I am to the point now that I just turn it off and plug it into the PC to charge if I am using USB. Otherwise, I just plug it into the wall with the adapter it came with and let it charge that way. I am not to pleased that now I can't have it charging and using it while plugged into the PC, but at least I can charge it with the PC now...