Scrolling in ETS behaves in a similar way to software such as Microsoft Outlook®, whereby ETS differentiates between scrolling with the mouse and with the bar.
Every time you scroll up or down in the Tree or List View, the content is refreshed at once. The scroll step is defined by the OS.
The content of the Tree or List View is only refreshed after the scroll bar has been released. The scroll step depends on the acceleration of the scroll bar movement. The consequence is that it is not possible to display the valid content for every position of the scroll bar.