Elevations of offset surface on profile are incorrect.
The Horizontal Chord Height Tolerance (File > Project Options - Tolerances tab) may be set too low. This parameter is used to control the number of points along a curve that are added during graphic display of spirals and horizontal circles. This parameter also affects the way surface features are imported from graphics. Additionally, when the profile is cut through the offset, InRoads uses the horizontal chord height tolerance to define the chords. This will in turn have an effect on the accuracy of the elevations in the offset.