This is the footnote I was referring to:

>> [27] Note that if failover of stateful session beans is implemented using bean passivation, the failover capability for such beans is not defined

Now, one of the main motivation, as per the spec, for disabling the passivation is:

>> Section 4.6.5 (Public final draft EJB 3.2 spec):

>> ... the Bean Provider can optionally configure the stateful session bean to prevent passivation of its instances.

>> For example, a stateful session bean instance *may contain non-serializable attributes which would lead to runtime exceptions during passivation*, or passivation and activation of such instances may cause degradation of application performance.

So if a user deployment is explicitly disabling passivation, for example due to non-serailizable attributes, IMO, it would be better to consider that bean non clusterable. However, if you or anyone else thinks that this shouldn't be handled this way, I'm open to making the relevant changes.