Dear Author,
the best way to report bugs is to register issue on Bugtracker, providing all necessary information (including OCCT version):
http://tracker.dev.opencascade.org
I can not reproduce the problem on current master with the following DRaw Harness script (note that option -setLineType has been added within #0025305 and will be available in OCCT 7.0.0):
pload MODELING VISUALIZATION box b1 0 0 0 1 2 3 box b2 3 0 0 2 3 1 vclear vclose ALL vinit View1 vaxo vdisplay b1 b2 vfit vaspects b1 -setcolor RED vaspects b2 -setcolor RED vaspects b1 -setLineType dotDash