str(DateTime('2000/01/01')) does not return '2000/01/01' but something like '2000/01/01 00:00:00 GMT+2'
Because of this, str(login_time) == '2000/01/01' is not True even if you log in the first time.

Conflicts:
	Products/CMFPlone/tests/testLoggedIn.py
Update change log.