There is a problem when using $('.dynatree-container') when you have more than one tree on the page, as this will try and select every tree with this class. I have lots of trees so I need to select the tree with a particular id... but I find, as did the previous person, that trying to select the tree by its id (eg '#tree') does not work. So, what will..? doing something like =$("#prevPageTree").dynatree("getTree").offset also does not work...
A few minutes later: ok, figured out how to do this. Spelunking around in the Chrome debugger shows that the .dynatree-container class is actually attached to the <ul> element inserted by dynatree under the #tree element used to initialize the dynatree instance. So you need to do something like
$("#tree ul").animate({ // animate the scrolling to the node
scrollTop: $(activeLi).offset().top - $('#tree ul').offset().top + $('#tree ul').scrollTop()
}, 'slow');
And if, like me, you don't want it to scroll the node right to the top of the window, then
scrollTop: $(activeLi).offset().top - $('#prevPageTree ul').offset().top + $('#prevPageTree ul').scrollTop() - 150
will nicely put your node 150 pixels down