hi skw, ctrl click on ANY button opens the button editor. All you need to do to set a keyboard trigger is first click on the button once to activate it or select the button by holding down shift and left clicking on it. Now you can hold down ctrl and press any keyboard key and you will be assigning that key to that scene.
What release date of the program do you have? you can find out by going to the "?" and clicking "About" and the release date will be in the splash window that appears, for example, June 8th 2010. Let me know how it goes.
Sincerely,