How do you remove the default "closed paths" option?

 Hi! i'm new to this site. i'm doing a textbook in biochemistry and am using corelDRAW 12 to design the flowcharts. i have a problem. i need to draw a number of arrows in the shape of a circle. so i thought i'd put a circle on the screen and then use the eraser tool to make breaks in the circle. then i'd have a number of curved line segments in the shape of a circle. problem is, every time i use the eraser on any portion of the circle, the two newly created nodes are automatically linked. now i need to disable the option that results in closed paths every time i erase a portion of a closed shape. i need to create breaks in the circle. so how do i disable the "Closed Paths" option? Help!