It seems that the Uno is not supposed to be able to be used to burn a bootloader to a new chip.
That's a lie. It works fine.
but it might work if my existing boot loader version on the Uno is the latest version of Optiboot.
The latest version of optiboot helps (you do not need to disable auto-reset) but is not required.
So, my question - how can I tell what revision of optiboot I am running on my Uno?
I believe westfw includes a version in the image and a sketch that returns the value. However...
I am relatively new to Arduino, buying my first board (Uno) just after Christmas and using Arduino 1.0 from day one.
...makes it very likely your board has the latest bootloader installed. Assuming you purchased an authentic board.
Can anyone say definitively if I can use my Arduino Uno as an ISP to program a bare chip?