In case anybody is interested, I was hitting a similar problem and here's what was happening in my case: EntityConverter#getAsObject() calls EntityManager#find(), but EntityManager#find() may return a proxy instead of the real object when there's already a proxy for the object in the session. Now, there's code in UISelectOne#matchValue (in JSF RI) that checks whether the value it received is in the list of select items: //Coerce the item value type before comparing values. Class type = value.getClass(); Object newValue; try { newValue = getFacesContext().getApplication(). getExpressionFactory().coerceToType(item.getValue(), type); } catch (ELException ele) { ... This coercion doesn't work since value.getClass() is a proxy class, whereas item.getValue() is plain MyObject, so it can't be coerced to the proxy type. Thus the effect is that I can't select some entities out of the list, while others are selectable just fine. I'm going to implement my own slightly hacked version of EntityStore Seam component to see if I can work around the issue. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4123768#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...