Eclipselink caching behaviour

I'm working on understanding the eclipselink cache, and I still have quite a way to go J

I have an entity with a single column primary key (String). If i use "em.find(key)", this is cached, so that repeated lookups don't go to the database. If i create a Query referring the  key ("select o from IkbPage o where key = ?1"), and then use query.getSingleResult(), it is not cached, and I see multiple identical queries.

Is there a configuration option I need to switch on?

Or is this just not possible?

Eirik