If you try to publish an assessment that has the same name as an assignment you created in the Gradebook, and you've configured the assessment (via Options) to send grades to the Gradebook, you'll receive the following error message:
Warning: A gradebook entry could not be created for this assessment. Please contact your local help desk for assistance.
To fix the problem, simply change the name of your assessment by at least one character (even adding a space to the title will work). Once the assessment's title is different from the Gradebook assignment's title, the assessment will publish correctly, and send its grades to the Gradebook.