I've already changed it in the couple places it happened, but just for future reference: it's rarely right for there to be a curb where two sidewalks intersect, since it shows on navigation systems for the visually impaired or wheelchair users that they have to go down and up the curb/ramp just to get between the two adjacent sidewalks. That's why you'll see little sidewalk nubs sticking out on the corners of intersections, so that the curb/ramp only applies to where the sidewalk meets the crossing.