i got some strange clipping plane behaviour in V6 when working with dimension and leader objects or curves using linetypes:
Dimensions are only clipped partially. On the positive side (where the clipping plane normal points to), i get dimension arrows shown, on the negative side they are hidden. This seems to be right but dimension lines are not clipped when they cross the clipping plane. If they are not crossing and totally on the negative side they are properly hidden. Dimension texts are clipped properly. When i select a clipping plane, it seems that some dimension lines, which are not crossing the clipping plane and are “behind” are shown but should remain hidden.
Using curves having a linetype assigned, eg. “DashDot” the clipping does not work when the plane intersects the curve. It does work when the curve is fully “behind” but falls apart as soon as the clipping plane is selected. Crossing curves are visible on the negative side of the clipping plane but can only be picked on the positive side. Leaders unfortunately have similar probs as dimensions over here.
Can you reproduce some of above points on your side ?