Thanks John for your quick reply.
Caps Lock (surprisingly) does not work (am on a Macbook Pro) and AutoAdvance only advances photos when I click on the star rating, so does not seem to have key board functionality (when I use Shift + 1 for example, the next photo does not automatically come up... again pretty weird).
(Adobe Bridge by the way perfectly accepts the 1,2,3... keys without needing to hit the Shift button)