zim 0.60 reports error when searching for "ftp01"

[Josef Möllers]

I was just searching (globally) for the string "ftp01" when ZIM threw this error report into my face:
I am running ZIM on Kubuntu 14.04, 64 bit.
I tried this two or three times with equal results, but eventually it succeeded. After having replaced all occurrences of "ftp01" by "ftp02" (which was the reason for my searching for "ftp01"), it has not happened again, nor has it happend when searching for "ftp02".

This is zim 0.60
Python version is sys.version_info(major=2, minor=7, micro=6, releaselevel='final', serial=0)
Gtk version is (2, 24, 23)
Pygtk version is (2, 24, 0)
Platform is posix
Zim revision is:
  branch: pyzim-trunk
  revision: 672 <email address hidden>
  date: 2013-04-30 19:27:20 +0200

======= Traceback =======
  File "/usr/lib/python2.7/dist-packages/zim/gui/searchdialog.py", line 91, in _search
    self.results_treeview.search(string)
  File "/usr/lib/python2.7/dist-packages/zim/gui/searchdialog.py", line 176, in search
    self.selection.search(self.query, callback=self._search_callback)
  File "/usr/lib/python2.7/dist-packages/zim/search.py", line 253, in search
    self.update(self._process_group(query.root, selection, callback))
  File "/usr/lib/python2.7/dist-packages/zim/search.py", line 352, in _process_group
    contentterms, results, scope, group.operator, callback)
  File "/usr/lib/python2.7/dist-packages/zim/search.py", line 496, in _process_content
    for page in generator:
  File "/usr/lib/python2.7/dist-packages/zim/notebook.py", line 1953, in walk
    for p in self.index.walk(path):
  File "/usr/lib/python2.7/dist-packages/zim/index.py", line 1223, in _walk
    for grandchild in self._walk(child, childpath):
  File "/usr/lib/python2.7/dist-packages/zim/index.py", line 1216, in _walk
    cursor.execute('select * from pages where parent = ? order by sortkey, basename', (path.id,))
InterfaceError: Error binding parameter 0 - probably unsupported type.