From the Django testing docs:
Running tests
Once you've written tests, run them using the test subcommand of your project's manage.py utility:
$ ./manage.py test
By default, this will run every test in every application in INSTALLED_APPS. If you only want to run tests for a particular application, add the application name to the command line. For example, if your INSTALLED_APPS contains 'myproject.polls' and 'myproject.animals', you can run the myproject.animals unit tests alone with this command:
$ ./manage.py test animals
Note that we used animals, not myproject.animals. New in Django 1.0: You can now choose which test to run.
You can be even more specific by naming an individual test case. To run a single test case in an application (for example, the AnimalTestCase described in the "Writing unit tests" section), add the name of the test case to the label on the command line:
$ ./manage.py test animals.AnimalTestCase
And it gets even more granular than that! To run a single test method inside a test case, add the name of the test method to the label:
$ ./manage.py test animals.AnimalTestCase.testFluffyAnimals
The last example should be applicable in your case.
If this is what you are doing, you'll need to post a more detailed description of the code employed in your test case.