TOldScrollPanel has been deprecated in favor of TScrollPanel. TOldScrollPanel allowed controls to exhibit fine grained control over scrolling. Most controls used the scroll bar position to indicate which row or column index was the first visible. This allowed scrolling on a per row and per column basis. TScrollPanel takes a different approach and allows scrolling on a per pixel basis. This means that a control has to indicate its size in pixels and the scroll panel takes care of scrolling the view port. A control can use TControl.GetVisibleRectangle() to determine which part is visible and should be painted.
Using TScrollPanel is much easier than using TOldScrollPanel. Also, TScrollPanel provides more convenient scrolling features, like scrolling by dragging a view port with right mouse button pressed.
All refactored controls have been tested but if one still encounters quirks in scrolling functionality, please let me know.