Blog Types: Error and how to display


I have installed and configured Blog Types plugin. I can now set the type of blog in the admin of a blog. However, upon doing so I receive error:

Warning: join() [function.join]: Invalid arguments passed in/wp-content/mu-plugins/blog-types.php on line 771

Question 2:

How do I display blog types in a widget or hook on my site? Ie: so end user can find blog by type.

Thanks in advance.