When you create the Object in the admin area, JFBConnect should add the object type automatically. Depending on your settings (mainly, if the "Built-in FB Object" setting is enabled) the namespace will be automatically added.
You should not have to use your own {SCOpenGraph type=xyz} tag on the page. If you're getting the error that the object isn't associated with the action, check:
1) The action is configured to work with the object. You need to check the right boxes in the bottom of the action configuration for any objects the action can work on.
2) Open the HTML on the page and search for "triggerAction". Make sure the URL specified is the correct page, is readable by guests (not a registered page) and when that page is viewed, has the correct og:type tags.
On a side note, just so you know, the {SCOpenGraph} tag supports an 'ns' variable to replace the namespace. So, on pages where you do want to specify the type, you can add:
{SCOpenGraph type=ns:blah}That's good so that you don't have to remember or change your namespace at a later date.
I hope that helps, but if not, let me know,
Alex