Upon closer inspection it looked like the column was catching the lip by no more than 1/8" or. After "going medeval" with a Dremel it looked like the problem was solved, but the bolts still didn't align very well. Some basic measurements showed that the center hole on my bracket was closer to the line going between the two other holes (i.e. they were closer along the Y axis than the holes on the table). All I had to do was to enlarge the center hole and the mill came together like a charm.