Comment 12 for bug 691608

I'm seeing a similar 'magic number' error when trying to start Calibre after the upgrade from Maverick to Natty:

Traceback (most recent call last):
  File "/usr/bin/calibre-server", line 18, in <module>
    from calibre.library.server.main import main
  File "/usr/lib/calibre/calibre/library/server/main.py", line 12, in <module>
    from calibre.library.server.base import LibraryServer
  File "/usr/lib/calibre/calibre/library/server/base.py", line 21, in <module>
    from calibre.library.server.content import ContentServer
  File "/usr/lib/calibre/calibre/library/server/content.py", line 14, in <module>
    from calibre.library.caches import SortKeyGenerator
  File "/usr/lib/calibre/calibre/library/caches.py", line 16, in <module>
    from calibre.utils.search_query_parser import SearchQueryParser
  File "/usr/lib/calibre/calibre/utils/search_query_parser.py", line 21, in <module>
    from pyparsing import CaselessKeyword, Group, Forward, \
ImportError: Bad magic number in /usr/lib/calibre/calibre/utils/pyparsing.pyc