ipad 1 ios5.1.1 jailbroken sometime, after 3 times in the last month, after I press the power button to turn off the screen, when I later want to turn it back on, it would not. The only way that I can turn it back on is to plug it in to a pc and press the power button and the home button together for about 10 seconds, then it will show the apple logo and then back to lock screen. Anyone know what is causing this behavior? Also, is there a solution to this? Thanks.