The code for GEOPAK Earthwork was changed from the 08.11.07.246 version to the newer versions 08.11.07.494 and above.
When the DGN elements are selected before processing traditional GEOPAK EW, a subset of code was written to remove duplicate elements if they are vertical or they turn-back on themselves. This was done for the processing of closed components in Corridor Modeler.
As a workaround there are a couple of options:
1. Make the lines so they are not quite verical.
2. When 2 sets of vertical lines are drawn in the same position, break the lines so they are not exactly the same.