I noticed you have most of your JPA properties set in the persistence.xml instead of the Spring configuration for your org.springframework.orm.jpa.LocalEntityManagerFactoryBean. So why the LocalEntityManagerFactoryBean and not org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean?
Not a big deal, just that you can have a very simple persistence.xml file with just the persistence name. Also the LocalContainer version give your more control. Check out the Spring docs on it.