The problem with that is that in MN, as I understand it, the optical scan ballot is kicked right back out to the voter if it is filled out ambiguously, and not recorded unless the voter corrects it (or confirms that they meant to leave a race blank.)
You could be right, but my understanding was that the ballots that make it through the scanner are ones that have proper votes for president and improper ones for senate.
I could be wrong on this.
A reference to the Dartmouth study (not that I trust Time magazine):
http://www.time.com/time/politics/article/0,8599,1859543,00.html