This was part-fixed in bug ticket 250, however, the following is not working :
double double_array[2] = {40, 2};
DrawSetStrokeDashArray(internd->drawing_wand, 2, double_array);
status = MagickDrawImage(intern->magick_wand, internd->drawing_wand);
it gets a Non-conforming drawing primitive definition (stroke-dash_array)
While I fixed the previously reported bug, obviously the complete code path was not tested. The fix is now available in Mercurial as changeset 13973:23f67c1bd69d and will be in today's development snapshot. Please test to verify that there are no additional problems.