Salat DateTime json deserialization issue

Global.scala

import play.api._

object Global extends GlobalSettings {
	
  override def onStart(app: Application) {
    com.mongodb.casbah.commons.conversions.scala.RegisterJodaTimeConversionHelpers()
    
    /*import com.mongodb.casbah.commons.conversions.scala._
    RegisterJodaTimeConversionHelpers()
    RegisterConversionHelpers()*/
    Logger.info("Application has started with JodaTime registered")
  }
}

salat_context.scala

package object salat_context {
  
  
  implicit val ctx = { 
    val context = new Context {
      val name = "CustomCtx"
      override val typeHintStrategy = StringTypeHintStrategy(when = TypeHintFrequency.WhenNecessary, typeHint = "_t")
      override val jsonConfig =  JSONConfig(objectIdStrategy = StringObjectIdStrategy,
          dateStrategy = TimestampDateStrategy())
    }
    //context.registerGlobalKeyOverride(remapThis = "id", toThisInstead = "_id1")
    com.mongodb.casbah.commons.conversions.scala.RegisterJodaTimeConversionHelpers() 
    context.registerClassLoader(Play.classloader)
    context
  }
   
}

TestItem.scala

package model


import play.api.Play.current
import util.salat_context._
import se.radley.plugin.salat._
import com.novus.salat.dao._
import com.novus.salat.annotations._
import com.mongodb.casbah.Imports._

import org.scala_tools.time.Imports.DateTime

case class TestItem(
		@Key("_id") id: ObjectId = new ObjectId, 
        name:String,
        date:Option[DateTime] = None
       ) 

object TestItem extends ModelCompanion[TestItem,ObjectId] {
  val collection = mongoCollection("TestItem")
  val dao = new SalatDAO[TestItem,ObjectId](collection = collection) {}
}

TestSpec.scala

package test

import org.specs2.mutable.Specification
import org.specs2.specification.Scope
import play.api.test.FakeApplication
import play.api.test.Helpers._
import org.bson.types.ObjectId
import model.TestItem
import org.specs2.mutable.Tags
import org.scala_tools.time.Imports.DateTime

import util.salat_context._

class TestSpec extends Specification with Tags{

  object FakeApp extends FakeApplication()
  
  "Test Item" should {
    "be converted to and from Json " in {
      running (FakeApp) {
    	  var testItem = TestItem(name="Test Item",date=Some(DateTime.now))
	      val jsonStr:String = TestItem.toCompactJson(testItem)  
	      println(jsonStr)
	      //jsonStr must not be null
	      val newItem = TestItem.fromJSON(jsonStr) 
	      newItem must not be null
      }
    } tag("testItem") 
  }
  
}