cannot import atk

I have a problem starting rhythmbox and gdebi-gtk with same problem.

rhythmbox command line output:

:~$ rhythmbox
/var/lib/python-support/python2.5/gtk-2.0/gtk/__init__.py:48: RuntimeWarning: tp_compare didn't return -1 or -2 for exception
  from gtk import _gtk
ImportError: could not import atk
ImportError: cannot import name Widget from gtk
ImportError: cannot import name ActionGroup from gtk
Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/artdisplay/__init__.py", line 76, in <module>
    class FadingImage (gtk.Misc):
AttributeError: 'module' object has no attribute 'Misc'

(rhythmbox:7645): Rhythmbox-WARNING **: Could not load plugin artdisplay

(rhythmbox:7645): Rhythmbox-WARNING **: Error, impossible to activate plugin 'Cover art'
Traceback (most recent call last):
  File "/usr/lib/rhythmbox/plugins/lyrics/__init__.py", line 25, in <module>
    import gtk, gtk.glade
ImportError: cannot import name Widget from gtk

(rhythmbox:7645): Rhythmbox-WARNING **: Could not load plugin lyrics

(rhythmbox:7645): Rhythmbox-WARNING **: Error, impossible to activate plugin 'Song Lyrics'

__________________________
gdebi-gtk command line output:

:~$ gdebi-gtk
/usr/lib/python2.5/site-packages/apt/__init__.py:18: FutureWarning: apt API not stable yet
  warnings.warn("apt API not stable yet", FutureWarning)
/var/lib/python-support/python2.5/gtk-2.0/gtk/__init__.py:48: RuntimeWarning: tp_compare didn't return -1 or -2 for exception
  from gtk import _gtk
ImportError: could not import atk
Traceback (most recent call last):
  File "/usr/bin/gdebi-gtk", line 31, in <module>
    from GDebi.GDebi import GDebi
  File "/usr/lib/python2.5/site-packages/GDebi/GDebi.py", line 35, in <module>
    import gtk, gtk.glade
ImportError: cannot import name Widget from gtk

info you may need for diagnose the problem:

:~$ dpkg -l python2.5 python-gobject python-gtk2 libgtk2.0-0 libglib2.0-0 python-glade2
Desired=Unknown/Install/Remove/Purge/Hold
| Status=Not/Installed/Config-f/Unpacked/Failed-cfg/Half-inst/t-aWait/T-pend
|/ Err?=(none)/Hold/Reinst-required/X=both-problems (Status,Err: uppercase=bad)
||/ Name Version Description
+++-==============-==============-============================================
ii libglib2.0-0 2.14.1-1ubuntu The GLib library of C routines
ii libgtk2.0-0 2.12.0-1ubuntu The GTK+ graphical user interface library
ii python-glade2 2.12.0-0ubuntu GTK+ bindings: Glade support
ii python-gobject 2.14.0-0ubuntu Python bindings for the GObject library
ii python-gtk2 2.12.0-0ubuntu Python bindings for the GTK+ widget set
ii python2.5 2.5.1-5ubuntu5 An interactive high-level object-oriented la

thank you!