Create related entities with rest endpoint

Hi,

I'm trying to use the rest create to create a custom entity and associated entities similar to the way this sample is doing from the MS website..

var account = {};
 account.Name = "Test Account Name";
 account.Description = "This account was created by the JavaScriptRESTDataOperations sample.";
 if (primaryContact != null) {
  //Set a lookup value
  writeMessage("Setting the primary contact to: " + primaryContact.FullName + ".");
  account.PrimaryContactId = { Id: primaryContact.ContactId, LogicalName: "contact", Name: primaryContact.FullName };

 }
 //Set a picklist value
 writeMessage("Setting Preferred Contact Method to E-mail.");
 account.PreferredContactMethodCode = { Value: 2 }; //E-mail//Set a money value
 writeMessage("Setting Annual Revenue to Two Million .");
 account.Revenue = { Value: "2000000.00" }; //Set Annual Revenue//Set a Boolean value
 writeMessage("Setting Contact Method Phone to \"Do Not Allow\".");
 account.DoNotPhone = true; //Do Not Allow//Add Two Tasksvar today = new Date();
 var startDate = new Date(today.getFullYear(), today.getMonth(), today.getDate() + 3); //Set a date three days in the future.var LowPriTask = { Subject: "Low Priority Task", ScheduledStart: startDate, PriorityCode: { Value: 0} }; //Low Priority Taskvar HighPriTask = { Subject: "High Priority Task", ScheduledStart: startDate, PriorityCode: { Value: 2} }; //High Priority Task
 account.Account_Tasks = [LowPriTask, HighPriTask]


Here it creates the account and adds 2 tasks to it.
I did a similar thing for my custom entity 

var competency = new Object();
competency.amd_Competency = {
	Id: this.id,
	LogicalName: 'amd_softindicator'
};

competency.amd_CMSId = {
	Id: cmsId,
	LogicalName: 'amd_cms'
}

competency.amd_name = "CMS Competency";
competency.amd_CompetencyLevel = {
	Id: $(this).find('input[:radio]:checked').val(),
	LogicalName: 'amd_competencylevel'
};

actionArray = new Array();
var actions = $('#actions tr').map(function () {
	var actionObj = new Object();

	actionObj.amd_actiondetail = $('textarea', $(this)).val();

	actionArray.push(JSON.stringify(actionObj));
});

competency.amd_amd_individualcompetency_amd_action = actionArray;

createRecord(competency, "amd_individualcompetency");

This works fine until i put the creation of the related entities in. The name of the entity relationshiop is correct however I keep getting the message
Error processing request stream. The property name 'amd_amd_individualcompetency_amd_action' specified for type 'Microsoft.Crm.Sdk.Data.Services.amd_individualcompetency' is not valid.
Any help appreciated.
Thanks
Chris