Oops...
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.com/ 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
Python traceback
Traceback (most recent call last): File "/usr/lib/python2.4/site-packages/trac/web/modpython_frontend.py", line 206, in handler dispatch_request(mpr.path_info, mpr, env) File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 139, in dispatch_request dispatcher.dispatch(req) File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 107, in dispatch resp = chosen_handler.process_request(req) File "/usr/lib/python2.4/site-packages/trac/ticket/query.py", line 410, in process_request self.display_csv(req, query) File "/usr/lib/python2.4/site-packages/trac/ticket/query.py", line 586, in display_csv results = query.execute(self.env.get_db_cnx()) File "/usr/lib/python2.4/site-packages/trac/ticket/query.py", line 139, in execute self.env.log.debug("Query SQL: " + sql % tuple([repr(a) for a in args])) File "/usr/lib/python2.4/logging/__init__.py", line 918, in debug apply(self._log, (DEBUG, msg, args), kwargs) File "/usr/lib/python2.4/logging/__init__.py", line 1039, in _log self.handle(record) File "/usr/lib/python2.4/logging/__init__.py", line 1049, in handle self.callHandlers(record) File "/usr/lib/python2.4/logging/__init__.py", line 1082, in callHandlers hdlr.handle(record) File "/usr/lib/python2.4/logging/__init__.py", line 617, in handle self.emit(record) File "/usr/lib/python2.4/logging/__init__.py", line 717, in emit self.handleError(record) File "/usr/lib/python2.4/logging/__init__.py", line 668, in handleError traceback.print_exception(ei[0], ei[1], ei[2], None, sys.stderr) File "/usr/lib/python2.4/traceback.py", line 125, in print_exception print_tb(tb, limit, file) File "/usr/lib/python2.4/traceback.py", line 67, in print_tb ' File "%s", line %d, in %s' % (filename,lineno,name)) File "/usr/lib/python2.4/traceback.py", line 13, in _print file.write(str+terminator) IOError: [Errno 28] No space left on device