Google Scholar has removed the functionality required for integration with Citations Helper with their new UI implementation. More information can be found in this sakai-dev post from Jon Dunn.
http://collab.sakaiproject.org/pipermail/sakai-dev/2012-May/017347.html
There is a temporary fix in trunk
Error rendering macro 'jira' : Unable to locate Jira server for this macro. It may be due to Application Link configuration.
which ensures that Google Scholar is launched with the old style (that included the needed link back to Citations Helper) for however long it's still available from Google.