gnome-disks does not mounts any images

[Bash]

After loading gnome-disks and choicing any iso-image (from menu "Disks>Attach Disk Image..."), program reports an error (see attachment).

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: gnome-disk-utility 3.6.1-1ubuntu1
ProcVersionSignature: Ubuntu 3.8.0-33.25-lowlatency 3.8.13.11
Uname: Linux 3.8.0-33-lowlatency i686
NonfreeKernelModules: fglrx
ApportVersion: 2.9.2-0ubuntu8.5
Architecture: i386
Date: Sun Nov 24 16:03:15 2013
ExecutablePath: /usr/bin/gnome-disks
InstallationDate: Installed on 2013-10-25 (29 days ago)
InstallationMedia: Ubuntu-Studio 13.04 "Raring Ringtail" - Release i386 (20130424)
MarkForUpload: True
ProcEnviron:
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=ru_RU.UTF-8
 SHELL=/bin/username
SourcePackage: gnome-disk-utility
UpgradeStatus: No upgrade log present (probably fresh install)

[Sebastien Bacher (seb128)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. The issue you are reporting is an upstream one and it would be nice if somebody having it could send the bug to the developers of the software by following the instructions at https://wiki.ubuntu.com/Bugs/Upstream/GNOME. If you have done so, please tell us the number of the upstream bug (or the link), so we can add a bugwatch that will inform us about its status. Thanks in advance.