In my new Premiere 7 the Transition Alignments default is set to "end at Cut", although the docs state that the default is "Center at Cut". I almost always want to use "Center at Cut". Can anyone tell me how to change the default?
Well, actually the program defaults to whichever is the most efficient placement, based on the clips you've placed it between and the presence of "head" and "tail" material.
In most cases, if you've got head and tail material (extra footage beyond the clips' cuts) the transition will center at cut. Otherwise, the program will center the transition over the clip with most head or tail material. With photos, there is no head or tail material, so it doesn't really matter where it sits.
If it bothers you, you can force the transition to Center at Cut by opening it in the Properties panel and selecting the option. But, if you don't have enough head or tail material, you may see a freeze frame of video during the transition.
There's much more to this, if you're interested. And I do a pretty thorough explanation, with illustrations, in my book Premiere Elements 7, available at Amazon and from http://www.muvipix.com.