[Edu-sig] Problem with mouse clicks

[Peter Drake]

I just had my students write this program in my CS0 class:

from graphics import *
graphics()

while 0 < 1:
     click = mouse()
     x = click[0]
     y = click[1]
     oval([x-10, y-10], [x+10, y+10])

(Note that graphics is Zelle's version with my procedural wrappers  
appended, http://www.lclark.edu/~drake/courses/cs0/graphics.py)

Usually (but, frustratingly, not every run), the mouse clicks are  
offset, so the circles appear some distance above and to the left of  
where they should.

Has anyone else run into this? Is there an explanation or workaround?

Peter Drake
http://www.lclark.edu/~drake/