Access control at a slave cluster instance

Hi all,

When a protected page (live area) is accessed form a slave cluster  
instance the following error occurs after the login :
<!--Can't create a modifiable session. Instance is running in  
clustered mode as slave.org.apache.cocoon.ProcessingException:  
Sitemap: error calling continuation at <map:call> - file:///Users/rudolfkorhummel/lenyacluster/slave1/build/lenya/webapp/lenya/modules/usecase/usecase.xmap:102:39org.apache.lenya.cms.repository.RepositoryException 
: Can't create a modifiable session. Instance is running in clustered  
mode as slave.full exception chain  
stacktraceorg.apache.cocoon.ProcessingException: Sitemap: error  
calling continuation ......
Is it impossible to have protected pages at a slave cluster instance ?
Best
Rudolf