I have a kindle fire too. I take screenshots by pressing the power button at same times as the volume button. The one that lowers the volume. You have to it at the same time though or else you'll just end up turning it off or just lowering the volume.
Press Home Button and Power off button at same time! Then it will work!
Thanks. I'll try that. I hope it works. If it does, maybe I'll post it.
Thanks so much! It worked!