Cannot use Fixtures.load(data.yml) in Bootstrap Job

I've attached a sample project that demonstrates the problem I'm having. I've tried both Play! 1.0 and 1.1 and can reproduce every time.

When using Fixtures.load("data.yml") in a Bootstrap Job (I followed the steps from the YABE tutorial), I get the following exception when the application loads (either in test or run mode; dev & prod) from first request:

@60g752c95
Internal Server Error (500) for request GET /@tests

Java exception (In /app/jobs/Bootstrap.java around line 15)
RuntimeException occured : Cannot load fixture data.yml: play.exceptions.UnexpectedException: Unexpected Error

play.exceptions.JavaExecutionException: Cannot load fixture data.yml: play.exceptions.UnexpectedException: Unexpected Error
 at play.jobs.Job.call(Job.java:120)
 at Invocation.Job(Play!)
Caused by: java.lang.RuntimeException: Cannot load fixture data.yml: play.exceptions.UnexpectedException: Unexpected Error
 at play.test.Fixtures.load(Fixtures.java:147)
 at jobs.Bootstrap.doJob(Bootstrap.java:15)
 at play.jobs.Job.doJobWithResult(Job.java:38)
 at play.jobs.Job.call(Job.java:111)
 ... 1 more
Caused by: java.lang.RuntimeException: play.exceptions.UnexpectedException: Unexpected Error
 at play.db.jpa.JPASupport.create(JPASupport.java:53)
 at play.test.Fixtures.load(Fixtures.java:132)
 ... 4 more
Caused by: play.exceptions.UnexpectedException: Unexpected Error
 at play.db.jpa.JPASupport.edit(JPASupport.java:139)
 at play.db.jpa.JPASupport.create(JPASupport.java:51)
 ... 5 more
Caused by: java.lang.NullPointerException
 at play.data.validation.Validation.error(Validation.java:84)
 at play.data.validation.Validation.addError(Validation.java:67)
 at play.data.binding.Binder.bindInternal(Binder.java:187)
 at play.data.binding.BeanWrapper.bind(BeanWrapper.java:47)
 at play.db.jpa.JPASupport.edit(JPASupport.java:64)
 ... 6 more
01:59:47,461 ERROR ~

refreshing the page, the error changes to:

@60g752c96
Error during job execution (jobs.Bootstrap)

Java exception (In /app/jobs/Bootstrap.java around line 15)
RuntimeException occured : Cannot load fixture data.yml: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of models.User.lastName

play.exceptions.JavaExecutionException: Cannot load fixture data.yml: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of models.User.lastName
 at play.jobs.Job.call(Job.java:120)
 at Invocation.Job(Play!)
Caused by: java.lang.RuntimeException: Cannot load fixture data.yml: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of models.User.lastName
 at play.test.Fixtures.load(Fixtures.java:147)
 at jobs.Bootstrap.doJob(Bootstrap.java:15)
 at play.jobs.Job.doJobWithResult(Job.java:38)
 at play.jobs.Job.call(Job.java:111)
 ... 1 more
Caused by: javax.persistence.PersistenceException: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of models.User.lastName
 at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
 at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:226)
 at play.db.jpa.JPASupport.save(JPASupport.java:148)
 at play.test.Fixtures.load(Fixtures.java:133)
 ... 4 more
Caused by: org.hibernate.PropertyAccessException: could not get a field value by reflection getter of models.User.lastName
 at org.hibernate.property.DirectPropertyAccessor$DirectGetter.get(DirectPropertyAccessor.java:58)
 at org.hibernate.property.DirectPropertyAccessor$DirectGetter.getForInsert(DirectPropertyAccessor.java:63)
 at org.hibernate.tuple.entity.AbstractEntityTuplizer.getPropertyValuesToInsert(AbstractEntityTuplizer.java:287)
 at org.hibernate.tuple.entity.PojoEntityTuplizer.getPropertyValuesToInsert(PojoEntityTuplizer.java:256)
 at org.hibernate.persister.entity.AbstractEntityPersister.getPropertyValuesToInsert(AbstractEntityPersister.java:3677)
 at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:290)
 at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:204)
 at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:130)
 at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:49)
 at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:154)
 at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:110)
 at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:61)
 at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:646)
 at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:620)
 at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:624)
 at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:220)
 ... 6 more
Caused by: java.lang.IllegalArgumentException: Can not set java.lang.String field models.User.lastName to models.User
 at org.hibernate.property.DirectPropertyAccessor$DirectGetter.get(DirectPropertyAccessor.java:55)
 ... 21 more
01:59:47,479 ERROR ~

I use the exact same .yml file for testing (test-data.yml) and have written full usage of the data in BasicTest.java. If I comment out the Fixtures.load("data.yml") line in Bootstrap.java, and launch in test mode, all the tests (which all load test-data.yml using Fixtures) pass fine. Yet when I try to bootstrap this data, it doesn't work.

I can't for the life of me see what I'm doing wrong, hence this bug report.