Hi,
CVS is not a theme. That folder appears there (and in every other folder) when you checkout OpenGoo from the CVS repository. It is recommended to install OpenGoo from the zip file that you can download at the website.
The theme is a config option in the database (og_config_options table). You need to set the value of the 'theme' config option of the 'general' category back to 'default'. You can do this with the following SQL query:
UPDATE `og_config_options` SET `value` = 'default' WHERE `category_name` = 'general' AND `name` = 'theme';