the scroll bar is being drawn off screen. Steps to recreate:
-Zoom in all the way vertically and horizontally
-click and drag the scroll bar to navigate downward.
-I make it to about track #234 before the scroll bar reaches the bottom of the screen
-Use the mouse scroll wheel to continue, and the scroll bar will be drawn off screen. I can only view tracks further than #234 if i use the mouse scroll wheel. Its as if cubase thinks my screen is a larger resolution than it is.
original post here: http://www.steinberg.net/forums/viewtopic.php?f=226&t=78307
[Mod Edit: Reported as solved in the linked thread]