graph_draw bug with edge_control_points

The following snippet produces an output with nice curvey edges:

from graph_tool import load_graph, Graph 
from graph_tool.draw import graph_draw 

g = Graph()                                                                                                                                                                         
g.add_vertex(4)                                                                                                                                                                     
pos = g.new_vertex_property('vector<float>')                                                                                                                                       
pos[g.vertex(0)] = [0, 0]                                                                                                                                                           
pos[g.vertex(1)] = [0, 1]                                                                                                                                                           
pos[g.vertex(2)] = [1, 0]                                                                                                                                                           
pos[g.vertex(3)] = [1, 1]                                                                                                                                                           
g.add_edge(g.vertex(0), g.vertex(3))                                                                                                                                               
g.add_edge(g.vertex(1), g.vertex(2))                                                                                                                                               
g.vertex_properties['pos'] = pos                                                                                                                                                   
ctl = g.new_edge_property('vector<float>') 
for e in g.edges(): 
    ctl[e] = [0, 0, 0.25, 0.2, 0.75, 0.2, 1, 0] 
graph_draw(g, pos=g.vp.pos, edge_control_points=ctl, output='tmp.eps') 

But when I replace the graph here with one loaded from the attached .gt file, I get no edges drawn at al. If I take out the pos argument though, the curvey edges come back.tmp.gt