What way have you been doing it to take screenshots? I have the recent update as well, but I have no problem taking screenshots. I have been using the power button plus home button method.
Do you just press it instantly, or do you hold down the power and home button? If you just press it for an instant, it won't work. If you have been holding it down, then I have no idea how to fix that, but there is another way to take screenshots, if that helps. Have you tried swiping the whole screen with the side of your hand?
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