Strangely enough, I was able to use the avisworld.com website on my computer at work. But I still can't use it at home (even after I tried deleting all the Avis-related cookies on that computer).
I was able to cancel my existing reservation and book a new one, so all is OK for now.
If Avis doesn't fix my Wizard account so that I can log in at avis.com (in response to the two e-mails I recently sent), I'll call and ask them to remove the AWD number from my profile, if that is what it takes!
Kathy