The tree pane vertical scroll bar can fail to reach up to three of the bottom items on the tree pane i.e. with the scroll bar at the bottom, the tree display is positioned such that there are up to three items still hidden off the botton of the pane.
To reproduce this here, I lift the bottom edge of the app window until the tree pane scroll bar appears.
Screen shot available.
EDIT(TC): Tracked at http://www.ventismedia.com/mantis/view.php?id=7022
1131 Tree pane vertical scroll fail [7022]
Moderator: Gurus