Here are a couple of threads that might help you out:
They are both more than a year old, but they may point you in the right direction. Are you using just your Drew username in the Account name field, rather than the whole firstname.lastname@example.org
? That seems to be a common problem with the error you're experiencing.
This could be a more complex problem, so I would also heed whatever the CNS folks have to say about the issue.