cannot save Xorg.conf file due to missing gtk python module

[David]

pre-requisites:

kubuntu 10.04, up to date

repo steps:

install the latest 'nvidia-current' package (sudo apt-get install nvidia-current)
configure xorg.conf (sudo nvidia-xconfig)
restart computer
invoke nvidia-settings (sudo nvidia-settings)
change video configuration in 'X Server Display Configuration' section
click on 'Save to X configure File' button, and click on 'Save' button on the prompted dialog

expected result:

xorg.conf file is saved successfully

actual result:

error message is popped up. "Unable to open X config file '/etc/X11/xorg.conf' for writing. the following error message is displayed in the console.
"
sh: pkg-config: not found
Traceback (most recent call last):
  File "/usr/share/screen-resolution-extra/nvidia-polkit.py", line 20, in <module>
    import gtk, gobject, sys, dbus, logging, os, re
ImportError: No module named gtk

ERROR: Unable to open X config file '/etc/X11/xorg.conf' for writing.
"

it looks like some gtk packages are missing.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.