Comment 23 for bug 418242

On a fresh install of Debian testing/unstable I've got this bug too.
uname -a: Linux alexander 2.6.38-2-amd64 #1 SMP Thu Apr 7 04:28:07 UTC 2011 x86_64 GNU/Linux
DE: XFCE 4.8
Inkscape 0.48.1 r9760, installed from official debian repository.

No clipboar monitoring program is installed. The problem is:

1. Start Inkscape with a blank document.
2. Create a rectangle.
3. Copy it with CTRL+C
4. Paste the rectangle with CTRL+V
5. Immediately appears a window, asking to install a package python-uniconvertor. If this package is installed, than another message appears:

UniConvertor failed:

/usr/lib/pymodules/python2.6/uniconvertor/app/utils/locale_utils.py:9: DeprecationWarning: The popen2 module is deprecated. Use the subprocess module.
  from popen2 import popen2
No plugin-type information in /usr/lib/pymodules/python2.6/uniconvertor/app/plugins/Filters/__init__.py
No plugin-type information in /usr/lib/pymodules/python2.6/uniconvertor/app/plugins/Filters/__init__.py
Cannot load plugin module sk1saver
Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/plugins.py", line 73, in load_module
    desc)
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/Filters/sk1saver.py", line 249, in <module>
    from app.Graphics.image import CMYK_IMAGE
ImportError: cannot import name CMYK_IMAGE
When importing plugin sk1saver
Traceback (most recent call last):
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/plugins.py", line 190, in __call__
    module = self.load_module()
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/plugins.py", line 73, in load_module
    desc)
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/Filters/sk1saver.py", line 249, in <module>
    from app.Graphics.image import CMYK_IMAGE
ImportError: cannot import name CMYK_IMAGE
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/lib/pymodules/python2.6/uniconvertor/__init__.py", line 88, in uniconv
    saver(doc, output_file)
  File "/usr/lib/pymodules/python2.6/uniconvertor/app/plugins/plugins.py", line 194, in __call__
    % {'name':self.module_name})
app.events.skexceptions.SketchError: Cannot load filter sk1saver

6. Pressing "OK" makes this window appears again for several times.

As it was mentioned earlier, killing xfce4-settings-helper stops this from happen.
Any suggestions?