How to configure failover for jBPM process instances in JBoss Enterprise SOA-P 5.x ?

Issue

• We are testing failover for jBPM processes. Our configuration looks something like following:
  • 2 servers with SOA-P in cluster (server profile: 'all')
  • 1 server with MySQL
• We have jBPM process with endless loop and state with timer inside this loop to proceed some tasks periodically.
  If we shutdown one node of jboss cluster, instance of process does not continue running on another node. In the jBPM console the instance is in state "running", but timer does not wake up the instance on remaining node anymore. The instance continues after we start first node again. The cluster is configured properly, ESB and JMS based service work properly after one node is down.

Why is the transition not done on the remaining node after timer expired?