addTo* not working with mockDomain

[paulwoods]

I'm having a problem getting addTo* method to work properly with mocked domains.

I'm using Win7 x64, java 1.6.0.21 and grails 1.3.4.

Here are my test classes (Foo and Bar are domain, and Alpha is a service)

package alpha

class Foo {

    String name
    
    static hasMany = [ bars : Bar ]
    
    static constraints = {
    }
    
    String toString() {
    	name
    }
}

package alpha

class Bar {

    String name
    
    static belongsTo = [ foo : Foo ]
    
    static constraints = {
    }
    
    String toString() {
    	name
    }
}

package alpha

class AlphaService {

    static transactional = true

    def load() {
    
    	def foo1 = new Foo(name:"foo1")
    	foo1.addToBars new Bar(name:"bar11")
    	foo1.addToBars new Bar(name:"bar12")
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
    	foo2.addToBars new Bar(name:"bar21")
    	foo2.addToBars new Bar(name:"bar22")
		foo2.save()
		
    }
}

package alpha

import grails.test.*

class AlphaServiceTests extends GrailsUnitTestCase {
    
    def service
    
    protected void setUp() {
        super.setUp()

		mockDomain Foo
		mockDomain Bar

        service = new AlphaService()
    }

    protected void tearDown() {
        super.tearDown()
    }

    void testLoad1() {
		
		service.load()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // fails - expected:<4> but was:<0>
		
    }

    void testLoad2() {
		
    	def foo1 = new Foo(name:"foo1")
    	foo1.addToBars new Bar(name:"bar11")
    	foo1.addToBars new Bar(name:"bar12")
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
    	foo2.addToBars new Bar(name:"bar21")
    	foo2.addToBars new Bar(name:"bar22")
		foo2.save()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // fails - expected:<4> but was:<0>
		
    }

    void testLoad3() {
		
    	def foo1 = new Foo(name:"foo1")
    	foo1.addToBars new Bar(foo:foo1, name:"bar11")
    	foo1.addToBars new Bar(foo:foo1, name:"bar12")
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
    	foo2.addToBars new Bar(foo:foo2, name:"bar21")
    	foo2.addToBars new Bar(foo:foo2, name:"bar22")
		foo2.save()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // fails - expected:<4> but was:<0>
		
    }

    void testLoad4() {
		
    	def foo1 = new Foo(name:"foo1")
		foo1.save()

    	foo1.addToBars new Bar(name:"bar11")
    	foo1.addToBars new Bar(name:"bar12")
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
		foo2.save()

    	foo2.addToBars new Bar(name:"bar21")
    	foo2.addToBars new Bar(name:"bar22")
		foo2.save()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // fails - expected:<4> but was:<0>
		
    }

    void testLoad5() {
		
    	def foo1 = new Foo(name:"foo1")
    	foo1.addToBars new Bar(name:"bar11").save()
    	foo1.addToBars new Bar(name:"bar12").save()
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
    	foo2.addToBars new Bar(name:"bar21").save()
    	foo2.addToBars new Bar(name:"bar22").save()
		foo2.save()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // fails - expected:<4> but was:<0>
		
    }

    void testLoad6() {
		
    	def foo1 = new Foo(name:"foo1")
    	foo1.addToBars new Bar(foo:foo1, name:"bar11").save()
    	foo1.addToBars new Bar(foo:foo1, name:"bar12").save()
		foo1.save()
		
    	def foo2 = new Foo(name:"foo2")
    	foo2.addToBars new Bar(foo:foo2, name:"bar21").save()
    	foo2.addToBars new Bar(foo:foo2, name:"bar22").save()
		foo2.save()
		
		assertEquals 2, Foo.list().size()
		assertEquals 4, Bar.list().size()  // success!
		
    }

}

When I run the tests, only testLoad6 passes. All of the other tests fail, indicating that no Bar objects have been saved.
Is there something I'm doing wrong with my code?
Can someone verify that they see the same problem?

Thanks,
Paul Woods