Import fails with memory error on files larger than 25MB

While using bzr-cvsps-import to import a CVS repository I received the following error when trying to import a CVS v file that was over 25MB.

bzr: ERROR: exceptions.MemoryError:

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 718, in run_bzr_catch_errors
    return run_bzr(argv)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 679, in run_bzr
    ret = run(*run_argv)
  File "/usr/lib/python2.4/site-packages/bzrlib/commands.py", line 375, in run_argv_aliases
    return self.run(**all_cmd_args)
  File "/usr/lib/python2.4/site-packages/bzrlib/plugins/cvsps/__init__.py", line 86, in run
    importer.process()
  File "/home/vantage/bzr-cvsps-import/cvsps/importer.py", line 1125, in process
  File "/home/vantage/bzr-cvsps-import/cvsps/importer.py", line 1068, in _process_patchsets
  File "/home/vantage/bzr-cvsps-import/cvsps/importer.py", line 649, in handle_patchset
  File "/home/vantage/bzr-cvsps-import/cvsps/importer.py", line 872, in _extract_changes
  File "/home/vantage/bzr-cvsps-import/cvsps/importer.py", line 375, in commit
  File "/usr/lib/python2.4/site-packages/bzrlib/repository.py", line 2057, in record_entry_contents
    ie.snapshot(self._new_revision_id, path, previous_entries, tree, self)
  File "/usr/lib/python2.4/site-packages/bzrlib/inventory.py", line 438, in snapshot
    work_tree, commit_builder)
  File "/usr/lib/python2.4/site-packages/bzrlib/inventory.py", line 453, in _snapshot_into_revision
    self._snapshot_text(previous_entries, work_tree, commit_builder)
  File "/usr/lib/python2.4/site-packages/bzrlib/inventory.py", line 722, in _snapshot_text
    self.text_sha1, self.text_size = commit_builder.modified_file_text(
  File "/usr/lib/python2.4/site-packages/bzrlib/repository.py", line 2104, in modified_file_text
    self._add_text_to_weave(file_id, new_lines, file_parents.keys())
  File "/usr/lib/python2.4/site-packages/bzrlib/repository.py", line 2120, in _add_text_to_weave
    versionedfile.add_lines(self._new_revision_id, parents, new_lines)
  File "/usr/lib/python2.4/site-packages/bzrlib/versionedfile.py", line 147, in add_lines
    return self._add_lines(version_id, parents, lines, parent_texts)
  File "/usr/lib/python2.4/site-packages/bzrlib/knit.py", line 687, in _add_lines
    return self._add(version_id, lines[:], parents, self.delta, parent_texts)
  File "/usr/lib/python2.4/site-packages/bzrlib/knit.py", line 752, in _add
    delta, self.factory.annotated)
  File "/usr/lib/python2.4/site-packages/bzrlib/knit.py", line 608, in _merge_annotations
    for i, j, n in seq.get_matching_blocks():
  File "/usr/lib/python2.4/site-packages/bzrlib/patiencediff.py", line 244, in get_matching_blocks
    len(self.a), len(self.b), matches, 10)
  File "/usr/lib/python2.4/site-packages/bzrlib/patiencediff.py", line 135, in recurse_matches
    for apos, bpos in unique_lcs(a[alo:ahi], b[blo:bhi]):
  File "/usr/lib/python2.4/site-packages/bzrlib/patiencediff.py", line 53, in unique_lcs
    index[line]= i
MemoryError