Import project operation does not work

Start with a clean copy of tvb.

Steps:
1. Select the default project
2. Run a simulation
3. Export the default project
4. Remove the default project
5. Import the exported project

Expected:
The datatypes resulted from the run simulation should also be imported.

Actual:
The datatypes resulted from the simulation are not imported.

The following exception is also thrown:

Traceback (most recent call last):
File "d:\work\tvb_trunk\tvb\core\services\importservice.py", line 99, in import_project_structure
self._import_project_from_folder(temp_folder)
File "d:\work\tvb_trunk\tvb\core\services\importservice.py", line 141, in _import_project_from_folder
self.import_project_operations(project_entity, new_project_path)
File "d:\work\tvb_trunk\tvb\core\services\importservice.py", line 193, in import_project_operations
self.store_datatype(datatype)
File "d:\work\tvb_trunk\tvb\core\services\importservice.py", line 272, in store_datatype
return dao.store_entity(datatype)
File "d:\work\tvb_trunk\tvb\core\entities\storage\rootDAO.py", line 58, in store_entity
raise excep
InterfaceError: (InterfaceError) Error binding parameter 15 - probably unsupported type. u'INSERT INTO "DATA_TYPES" (gid, type, module, subject, state, visible, invalid, is_nan, create_date, disk_size, user_tag_1, user_tag_2, user_tag_3, user_tag_4, user_tag_5, fk_parent_burst, fk_datatype_group, fk_from_operation) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)' ('163c8bb0-0970-11e2-bab5-bc7737d8282b', 'TimeSeriesRegion', 'tvb.datatypes.time_series', 'John Doe', 'INTERMEDIATE', 1, 0, 0, '2012-09-28 16:28:22.990000', None, 'conn_74', None, None, None, None, 1, None, 6)