Yes there is a scroll bar but it doesnt work very often (I'm talking about p8) - it happens that the scroll bar is disabled when the graph is cut from top or bottom - you cannot expand it. The only solution is to change the frame - than scroll bar becames active and you can resize it.

Also when changing parameters directly from the graph window the dial's value (in properties window) sometimes doesnt get updated - and again only changing frame helps. but it's not so good for me since when graph window is active no keyboard shortcuts for advancing frames are working on my p8 version :(