I'm unable to reproduce this warning on a clean RHEL6 install.

The warning just means GTK+ is unable to load the PackageKit module, which is provided by the "PackageKit-gtk-module" package:

    $ rpm -ql PackageKit-gtk-module
    /usr/lib/gtk-2.0/modules/libpk-gtk-module.so
    ...

The "gnome-packagekit" package installs the GConf key

    /apps/gnome_settings_daemon/gtk-modules/pk-gtk-module

which is what tells GTK+ to try to load the PackageKit module in the first place.

This sounds like a configuration issue on your system.  Can you verify that these two packages are installed?

I don't have PackageKit-gtk-module nor gnome-packagekit installed:

[root@vmware178 ~]# rpm -qf /usr/lib/gtk-2.0/modules/libpk-gtk-module.so
error: file /usr/lib/gtk-2.0/modules/libpk-gtk-module.so: No such file or directory
[root@vmware178 ~]# rpm -q gnome-packagekit
package gnome-packagekit is not installed
[root@vmware178 ~]# rpm -q pygtk2
pygtk2-2.16.0-3.el6.i686
[root@vmware178 ~]# python -c 'import gtk'
Gtk-Message: Failed to load module "pk-gtk-module": libpk-gtk-module.so: cannot open shared object file: No such file or directory
[root@vmware178 ~]# rpm -q PackageKit-gtk-module
package PackageKit-gtk-module is not installed
[root@vmware178 ~]# 

That's what's interesting -- the package dependencies allowed me to install the packages this way, yet I still get error about that pk-gtk-module thing.

Its a harmless message. Clearly not a blocker.

Development Management has reviewed and declined this request.  You may appeal
this decision by reopening this request.

I do not agree that this is user environment issue.

Yes, if I install PackageKit-gtk-module (which pulls in libarchive comps-extras PackageKit-yum-plugin PackageKit-yum PackageKit-glib PackageKit), the message goes away. But if I remove them again, the message is back. And there is no dependency which would prevent me from doing that.

So something in the way pygtk2 (or maybe other package) is built assumes PackageKit-gtk-module installed (or at least one file from that package) which is incorrect and signals some packaging problem.

If you want updated Steps to Reproduce, they will be something like:

1. Make sure pygtk2 is installed.
2. Make sure PackageKit-gtk-module and its dependencies are not installed:
   # yum remove libarchive comps-extras PackageKit-yum-plugin PackageKit-yum PackageKit-glib PackageKit PackageKit-gtk-module
3. Run # python -c 'import gtk'

Reopening per advice in comment 6, setting flag rhel‑6.1.0.

Can you try doing:

gconftool-2 -u /apps/gnome_settings_daemon/gtk-modules/pk-gtk-module

And then logging out and back in.

(In reply to comment #8)
> Can you try doing:
> 
> gconftool-2 -u /apps/gnome_settings_daemon/gtk-modules/pk-gtk-module
> 
> And then logging out and back in.    

Done that on that RHEL 6, no change.

Ummm, am I supposed to run the command on my local workstation (Fedora 12) or on the virtual machine (RHEL 6)?

This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unfortunately unable to
address this request at this time. Red Hat invites you to
ask your support representative to propose this request, if
appropriate and relevant, in the next release of Red Hat
Enterprise Linux. If you would like it considered as an
exception in the current release, please ask your support
representative.

This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
in the current release, Red Hat is unable to address this
request at this time.

Red Hat invites you to ask your support representative to
propose this request, if appropriate, in the next release of
Red Hat Enterprise Linux.

Closing.