calibre crashed with ImportError in <module>()

Binary package hint: calibre

Traceback (most recent call last):
  File "/usr/bin/calibre", line 8, in <module>
    load_entry_point('calibre==0.4.136', 'gui_scripts', 'calibre')()
  File "/usr/lib/python2.5/site-packages/pkg_resources.py", line 277, in load_entry_point
    return get_distribution(dist).load_entry_point(group, name)
  File "/usr/lib/python2.5/site-packages/pkg_resources.py", line 2180, in load_entry_point
    return ep.load()
  File "/usr/lib/python2.5/site-packages/pkg_resources.py", line 1913, in load
    entry = __import__(self.module_name, globals(),globals(), ['__name__'])
  File "/usr/lib/python2.5/site-packages/calibre/gui2/main.py", line 39, in <module>
    from calibre.gui2.tools import convert_single_ebook, convert_bulk_ebooks, \
  File "/usr/lib/python2.5/site-packages/calibre/gui2/tools.py", line 14, in <module>
    from calibre.gui2.dialogs.epub import Config as EPUBConvert
  File "/usr/lib/python2.5/site-packages/calibre/gui2/dialogs/epub.py", line 18, in <module>
    from calibre.ebooks.epub.from_any import SOURCE_FORMATS, config as epubconfig
  File "/usr/lib/python2.5/site-packages/calibre/ebooks/epub/__init__.py", line 13, in <module>
    from calibre.ebooks.html import config as common_config, tostring
  File "/usr/lib/python2.5/site-packages/calibre/ebooks/html.py", line 30, in <module>
    from cssutils import CSSParser
  File "/usr/lib/python2.5/site-packages/cssutils/__init__.py", line 87, in <module>
    import util
  File "/usr/lib/python2.5/site-packages/cssutils/util.py", line 16, in <module>
    import encutils
ImportError: No module named encutils

ProblemType: Crash
Architecture: amd64
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/calibre
InterpreterPath: /usr/bin/python2.5
NonfreeKernelModules: nvidia
Package: calibre 0.4.136+dfsg-0ubuntu1
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/bin/calibre
ProcEnviron:
 SHELL=/bin/bash
 PATH=(custom, user)
 LANG=en_US.UTF-8
PythonArgs: ['/usr/bin/calibre']
SourcePackage: calibre
Title: calibre crashed with ImportError in <module>()
Uname: Linux 2.6.28-8-generic x86_64
UserGroups: adm admin cdrom dialout lpadmin mythtv plugdev sambashare