When moving a line object with the mouse you will hit the left most side of a form. However, using the arrow keys you can move a line object beyond the left most edge of the form.
When a line extends beyond the right most edge of a form and the form is shown in a tab panel then the line is not cut off within the tab panel. It exends the full width of the current form being shown.
Also, line resizing using arrow keys and modifiers still does not work in 1.2
Win XP/ 1.2 Release