I also am having an issue with the widget, the sound button will not remove from the widget. The things I am trying to have are wifi/bluetooth/gps/screen rotation/led light, and if I check and uncheck sound it does not go away, I have tried rebooting after unchecking. When there are 5 things checked I try to check and then uncheck sound (hoping it will go away) and it says only 6 items are allowed (5 items are checked).
I have tried disabling the power widget and rebooting (without sound checked at all) and nothing changes, the bar does not disable/go away, and the sound button does not go away either.
Not a huge concern I suppose, I just prefer not to have that button there.