Hi,
When you say the map is not displaying – do you mean you can’t edit it in the post editor or you don’t see it when you view your blog? If it’s the latter, please see the FAQ, it’s usually theme related.
If that doesn’t help: please let me know what version you upgraded from, and provide a URL where I can view the problem. If it’s an issue in the post editor, please also send a login so I can check it (you can use the contact form).