Unittest with selenium works flawlessy in python but gives import error with django manage.py test

I have this file, generated from Selenium IDE

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import Select
from selenium.common.exceptions import NoSuchElementException
import unittest, time, re

class Tcase(unittest.TestCase):
    def setUp(self):
        self.driver = webdriver.Firefox()
        self.driver.implicitly_wait(30)
        self.base_url = "http://localhost:9999/"
        self.verificationErrors = []

    def test_tcase(self):
        driver = self.driver
        driver.get(self.base_url)
        # other things...

    def is_element_present(self, how, what):
        try: self.driver.find_element(by=how, value=what)
        except NoSuchElementException, e: return False
        return True

    def tearDown(self):
        self.driver.quit()
        self.assertEqual([], self.verificationErrors)

if __name__ == "__main__":
    unittest.main()

I'm working on a Django project (1.4) and python 2.6, which i want to test with Selenium.

if i run this file directly from python it works without problems.

if i run this doing

python manage.py test myapp

i get import error

C:\web\opineo> python .\manage.py test core
Traceback (most recent call last):
  File ".\manage.py", line 14, in <module>
    execute_manager(settings)
  File "C:\Python26\lib\site-packages\django\core\management\__init__.py", line 459, in execute_manager
    utility.execute()
  File "C:\Python26\lib\site-packages\django\core\management\__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python26\lib\site-packages\django\core\management\commands\test.py", line 49, in run_from_argv
    super(Command, self).run_from_argv(argv)
  File "C:\Python26\lib\site-packages\django\core\management\base.py", line 196, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "C:\Python26\lib\site-packages\django\core\management\base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "C:\Python26\lib\site-packages\south-0.7.3-py2.6.egg\south\management\commands\test.py", line 8, in handle
    super(Command, self).handle(*args, **kwargs)
  File "C:\Python26\lib\site-packages\django\core\management\commands\test.py", line 72, in handle
    failures = test_runner.run_tests(test_labels)
  File "C:\Python26\lib\site-packages\django\test\simple.py", line 380, in run_tests
    suite = self.build_suite(test_labels, extra_tests)
  File "C:\Python26\lib\site-packages\django\test\simple.py", line 264, in build_suite
    suite.addTest(build_suite(app))
  File "C:\Python26\lib\site-packages\django\test\simple.py", line 79, in build_suite
    test_module = get_tests(app_module)
  File "C:\Python26\lib\site-packages\django\test\simple.py", line 36, in get_tests
    test_module = import_module('.'.join(prefix + [TEST_MODULE]))
  File "C:\Python26\lib\site-packages\django\utils\importlib.py", line 35, in import_module
    __import__(name)
  File "C:\web\opineo\core\tests\__init__.py", line 3, in <module>
    from core.tests.func import *
  File "C:\web\opineo\core\tests\func.py", line 1, in <module>
    from selenium import webdriver
  File "C:\web\opineo\core\tests\selenium.py", line 3, in <module>
    from selenium import webdriver
ImportError: cannot import name webdriver

what's wrong? the selenium files are there! in site-packages of Python 2.6

EDIT:

this works, as expected it opens Firefox

PS C:\web\opineo> python.exe .\manage.py shell
Python 2.6.6 (r266:84297, Aug 24 2010, 18:46:32) [MSC v.1500 32 bit (Intel)] on win32
>>> from selenium import webdriver
>>> driver = webdriver.Firefox()