in pyqt application overlay scrollbar does not work

[f0ma]

Scroll bar in pyqt application totally hide, and in console I see errors:

(python:16395): Gtk-CRITICAL **: IA__gtk_widget_style_get: assertion `GTK_IS_WIDGET (widget)' failed

Starting application with LIBOVERLAY_SCROLLBAR=0 fix problem.

OS:
Description: Ubuntu 12.04 LTS
Release: 12.04
overlay-scrollbar 0.2.16+r348-0precise3

Step to reproduce:
1. Create ui file (at example Dialog) with QTextEdit widget (I used qt creator), and save it as "dialog.ui".
2. Convert file to .py (pyuic4 dialog.ui -o dialog.py)
3. Execute python script to show dialog:

from PyQt4 import QtGui
from PyQt4 import QtCore
import dialog
import sys

class Dialog(QtGui.QDialog):
 def __init__(self, parent=None):
  QtGui.QWidget.__init__(self, parent)
  self.ui = dialog.Ui_Dialog()
  self.ui.setupUi(self)

app = QtGui.QApplication(sys.argv)
dlg = Dialog()
dlg.show()
sys.exit(app.exec_())

[f0ma (f0ma)]

We can disable overlay from python program itself:

import os
os.environ['LIBOVERLAY_SCROLLBAR'] = '0'