I don't believe any of them work right now. What does work (though is a little bit of a pain), plug the phone into your computer, get all the drivers installed (should be done from root). go to the android SDK folder, in tools there is something called ddms.bat, launch that. Then select the device, and under one of the menus is screen shot.
this works whether you are rooted or not, just make sure all your drivers are working right.