Bug inside GtkBuilder w/ GtkAdjustment

[Matteo Landi <landimatte gmail com>]

Today working with glade, I noticed a strange behaviour while working
with GtkAdjustment.

import gtk

str_gui = """
<?xml version="1.0"?>
<interface>
  <requires lib="gtk+" version="2.16"/>
  <!-- interface-naming-policy project-wide -->
  <object class="GtkAdjustment" id="foo">
    <property name="value">10</property>
    <property name="lower">1</property>
    <property name="upper">100</property>
    <property name="step_increment">1</property>
  </object>
</interface>
"""

builder = gtk.Builder()
builder.add_from_string(str_gui)
print builder.get_object('foo').get_value()

The output is 0.0 and not 10 as espected. Is this something already known?
Thanks in advance.

-- 
Matteo Landi
http://www.matteolandi.net/