I guess if you're using only local references, no remote, you weren't getting any benefit from load balancing across the cluster in the first place. Is that right? If so, caching them should do no harm. We used to cache remote (before local existed) and had trouble recovering from stale instances - say the remote server had been stopped and restarted since you got the reference. You might want to try the EJB forum (top of the list!) to get the real EJB experts involved.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi