graph_draw draws the graph upside down if a vertex has more than three self loops

Under graph_tool 2.2.31 '(commit 245d1e2c, Thu Mar 27 11:28:39 2014 +0100)' Using input XML file

<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">

  <key id="key0" for="node" attr.name="vtext" attr.type="string" />

  <graph id="G" edgedefault="undirected" parse.nodeids="canonical" parse.edgeids="canonical" parse.order="nodesfirst">

    <node id="n0">
      <data key="key0">My Label</data>
    </node>

    <edge id="e5" source="n0" target="n0" />
    <edge id="e7" source="n0" target="n0" />
    <edge id="e8" source="n0" target="n0" />
  </graph>
</graphml>

I get the following image with graph_draw, using the internal vtext property as vertex labels: strangefail

This inversion occurs both in png output and in the interactive window (and causes problems to the interactive vertex selection). I suspect it is due to the presence of 3 looping edges on the node, it doesn't occur with 1 or 2 self loops.

Regards