its a bit inconvenient that context menus have zero tolerance on mouse temporarily exit / mouse out.
So if you hover over context menu item with submenu, the submenu opens.
If you want to select something in the submenu, you have to go straight with the mouse-pointer to the submenu without leaving the context menu line. If you leave the straight line once. the submenu closes.
For example MS Windows XP has a timeout on closing submenus on mouseout. Only if you have left the context menu hovered more than e.g. 0,5 seconds then the sub-context menu disappers.
Not very importand but i notice that every day.