If you're not quite sure you are getting circles instead of ovals, try out my new, patent-worthy-but-idontmeanthat invention: the roundness detector! Made to fit a fender washer so you have something round to compare it to. Auto-aligning, too. Isn't that special?
If you download now, we'll throw in the "quicklash" calibration test. Get it ballparked in with the Round-ness Detector and then fine tune with quicklash.