In the manual I read this. But I don’t understand what they mean. A screenshoot would help.
p. 42
To change the number of rows in which the tools are arranged on the toolbox,
• keep the right mouse button pressed on the toolbox until the mouse pointer changes to a double arrow,
• and drag to the bottom or right.
The tools can be arranged in one, two, or three horizontal or vertical rows.
You forgot some important part of the quotes.
• Toopenthetoolboxbyright-clicking(Win)/[Ctrl]-click- ing (Mac), activate the “Popup Toolbox on Right Click” option in the Preferences dialog (Editing–Tools page). > When this option is activated, you need to press any modifier key and right-click (Win)/[Ctrl]-click (Mac) to open the context menu. When it is deactivated, you need to press a modifier key to open the toolbox instead of the context menu.
Basically the toolbox is something you can enable via your preferences.
Screenshot:
https://dl.dropbox.com/u/1885149/cub_toolbox_option.png
Once this option is selected, when you right click, a toolbox will show rather than the context menu. Screenshot of the toolbox:
https://dl.dropbox.com/u/1885149/cub_tollbox.png
That allows you to easily select different tools, if for some crazy unexplained reason, you choose to select tools by mouse clicks rather than easy to use keyboard shortcuts 
Furthermore, when that option is selected (right click for toolbox)…if you click and hold the right mouse button, after a second or two a crosshair will appear that will allow you to resize the toolbox. As shown in the screenshot above, it is one long row. You can resize it to be multiple rows.
Hope that helps.
I right click, the toolbar appear. I leave my mouse down pressed, but the 2 arrows (Crossair) don’t show.