Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.

Since you only requested a single operation it is extremely likely that
the package is simply not installable and a bug report against
that package should be filed.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  libapache-mod-python2.3: Conflicts: libapache-mod-python2.4 but 2:2.7.10-4ubuntu1 is to be installed
  libapache-mod-python2.4: Conflicts: libapache-mod-python2.3 but 2:2.7.10-4ubuntu1 is to be installed
  libapache2-mod-python2.4: Conflicts: libapache-mod-python2.3 but 2:2.7.10-4ubuntu1 is to be installed
  python2.3-apoo: Conflicts: python2.4-apoo but 1.3-4ubuntu1 is to be installed
  python2.3-cherrypy2.1: Conflicts: python2.3-cherrypy but 2.0.0f-2 is to be installed
  python2.3-codespeak-lib: Conflicts: python2.3-pylib but 0.7.20050829-0ubuntu1 is to be installed
  python2.3-psycopg: Depends: python2.3-egenix-mxdatetime but it is not installable
  python2.4-cherrypy2.1: Conflicts: python2.4-cherrypy but 2.0.0f-2 is to be installed
  python2.4-codespeak-lib: Conflicts: python2.4-pylib but 0.7.20050829-0ubuntu1 is to be installed
  python2.4-pyorbit-omg: Conflicts: python2.4-omniorb2-omg but 2.6-2ubuntu1 is to be installed
  python2.4-pysqlite1.1: Conflicts: python2.4-sqlite but 1.0.1-4ubuntu1 is to be installed
  python2.4-schoolbell: Depends: zope3 (>= 3.2) but it is not going to be installed
                        Depends: zope3 (<= 3.3) but it is not going to be installed
  python2.4-sqlite: Conflicts: python2.4-pysqlite1.1 but 1.1.6-2 is to be installed