I don't know how PE Design works. I have Digitizer Pro/MB and to digitize curves in Pro you have to right click the mouse. So it is left click for a straight line and right click for a curved line. Or if you are using a pen and digitizing tablet,you can digitize a curved line by pressing on the bottom button.
I hope that was what your were asking and that this helps.
Otherwise reads the instructions that came with PE Design. It should tell you in there how to digitize curves.
WEEL THEY SAY IT IS NOT POSIBLE BUT I HAVE REAL ROND STAMPS !! I CAN'T STAND IT .. I DRAW WITH A PEN I AM GONNA TRY IT !!
Back to the top for someone who can answer. Hope you can get your answer