Dash / post publishing access level for Members

Hi

I would like my users signed up to 'business' level - to be able to add a vacancy/post. I have set these up using the custom post type plugin.
At the moment it is saying they don't have sufficient permissions to access the page -

http://www.students4work.co.uk/wp-admin/edit.php?post_type=vacancies

As an added complication, they should only be able to see / access their own vacancy posts in the admin.

What settings do I need to ensure are in place within the membership plugin access levels to achieve this?

Regards
Mark