gdebi-gtk crashed with AttributeError in open(): 'GDebi' object has no attribute '_cache'

I have used in GDebi

Menu -> File -> Open and choosed a virtualbox4.2.4 .deb file for installing.

During this the crasher was detected by apport.

GDebi was frozen some seconds, but not killed at all.

The following VirtuBox installation run with success.

Steps to reproduce:
---------------------------

1. Donwload the VirtualBox deb for Ubuntu12.10 Quantal from :

download.virtualbox.org/virtualbox/4.2.4/virtualbox-4.2_4.2.4-81684~Ubuntu~quantal_amd64.deb

2.Open GDebi
3.Choose in Gdebi: Menu -> File -> Open
4.Choose the VirtualBox4.2.4 .deb downloaded in Step 1 and click open
5.See the crasher during this actions
6.The package install itself runs smooth, once induced.

ProblemType: Crash
DistroRelease: Ubuntu 12.10
Package: gdebi 0.8.5ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-18.29-generic 3.5.7
Uname: Linux 3.5.0-18-generic x86_64
ApportVersion: 2.6.1-0ubuntu6
Architecture: amd64
Date: Mon Oct 29 17:19:05 2012
ExecutablePath: /usr/share/gdebi/gdebi-gtk
InstallationDate: Installed on 2012-07-22 (98 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120722)
InterpreterPath: /usr/bin/python2.7
MarkForUpload: True
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/gdebi-gtk
ProcEnviron:
 PATH=(custom, no username)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/gdebi-gtk']
SourcePackage: gdebi
Title: gdebi-gtk crashed with AttributeError in open(): 'GDebi' object has no attribute '_cache'
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo