If you think this really should work and you can reproduce it. Then you should consider to report this problem to the Trac team.
Go to http://trac.edgewall.org/ and create a new ticket where you describe the problem, how to reproduce it. Don't forget to include the python traceback found below.
TracGuide — The Trac User and Administration Guide
Traceback (most recent call last):
File "/var/lib/python-support/python2.4/trac/web/main.py", line 387, in dispatch_request
dispatcher.dispatch(req)
File "/var/lib/python-support/python2.4/trac/web/main.py", line 237, in dispatch
resp = chosen_handler.process_request(req)
File "/var/lib/python-support/python2.4/trac/ticket/web_ui.py", line 279, in process_request
self._do_save(req, db, ticket)
File "/var/lib/python-support/python2.4/trac/ticket/web_ui.py", line 546, in _do_save
cnum=internal_cnum):
File "/var/lib/python-support/python2.4/trac/ticket/model.py", line 250, in save_changes
(self.id, when, author, cnum, comment))
File "/var/lib/python-support/python2.4/trac/db/util.py", line 50, in execute
return self.cursor.execute(sql_escape_percent(sql), args)
File "/usr/lib/python2.4/site-packages/sqlite/main.py", line 237, in execute
self.con._begin()
File "/usr/lib/python2.4/site-packages/sqlite/main.py", line 503, in _begin
self.db.execute("BEGIN")
OperationalError: database is locked