I just learned that setting up the Kindle Countdown promotion has to be done separately for each marketplace. There are only two at the moment (amazon.com & amazon.co.uk).
I enabled the .99 promotion for amazon.co.uk today and it will go into effect on Saturday, Jan 25.
You can find Shaper of Stone at the UK site by going to http://www.amazon.co.uk/Shaper-Stone-Keith-Keffer-ebook/dp/B00CMHEBJK
The URL for the US site is http://www.amazon.com/Shaper-Stone-Keith-Keffer-ebook/dp/B00CMHEBJK