When a non-registered user requests a tutor session from the search results page, they are taken to this page: http://dev.voluntutor.tk/?q=node/21. Here it says, Access denied, not authorized to view page. There should be instructions on this page telling users to register in order to make an appointment with tutor. The link to take them to where they can register is another bug
The message should tell them to use the links on the left of the page to register. There is no need for a link to the home page.
Suggestion:
Customize the access denied page such that if the user is not logged in, they are shown the error but with both the login fields and initial 'create account' forms. This would save the user a step to do these if they choose and may also streamline the process for users who just identified a tutor they'd like to request.