GeoWin Utilities
This will allow 3D Polylines (and 3D lines) to
show non-continuous linteypes correctly..
Toolbar:

will
display linetypes on 3D Polylines and Lines,
from command
line:
sngLTOn

will turn
it back off, ,
from command line:
sngLTOff
.
Normal display
display of line types ON