Thanks for your replies. I understand your point - the 4 methods of SFSBs are in the unspecified tx context and thus no set/getRollbackOnly() can be called. Anyways, in page 81 of the spec it is also said:
The reasons for disallowing the operations in Table 2 follow:
...
� Invoking the getRollbackOnly and setRollbackOnly methods is disallowed in the
session bean methods for which the Container does not have a meaningful transaction context,
and to all session beans with bean-managed transaction demarcation.
...
� Accessing resource managers and enterprise beans is disallowed in the session bean methods for which the Container does not have a meaningful transaction context or client security context.
This quote is very annoying from the logical perspective; how come the 4 methods
can access resource managers and ejbs (and thus they seem to have meaningful tx context), but they
cannot access the aforementioned get/setRollbackOnly() methods (and thus they do not have a meaningful tx context

?