Appcelerator Register with custom fields

register.js

var sex = (male == 1) ? 'male' : 'female';
		var data = {
		      email: email.value, 
		      first_name: global.user_names[0], 
		      last_name: global.user_names[1], 
		      password: password.value, 
		      password_confirmation: password.value,
		      custom_fields: '{ "dob": "'+ dob.value +'", "sex": "'+ sex +'" }' // REMOVE THIS LINE IT ALL WORKS... HAVE HAD MULTIPLE PEDRMEATATIONS, SO THIS WAY MAY NOT BE THE ONLY CAUSE OF THIS NOT WORKING, JUST THE LAST ONE I TRIED.
		};
		sdk.sendRequest('users/create.json', 'POST', data, false, callback);

		function callback(data) {
			if(data) {
				if(data.meta) {
					var meta = data.meta;
					if(meta.status == 'ok' && meta.code == 200 && meta.method_name == 'createUser') {
						var message = '';
						var user = data.response.users[0];
						Ti.API.info("User id is => " + user.id);
						var cred = [user.id, email.value];
						Ti.App.Properties.setString('credentials', cred);
						keychain.setPasswordForService(password.value, 'Heritage', email.value);
						Ti.App.fireEvent('accountLoggedIn');
					} else{
						alert(meta.status +' ' + meta.code)
					}
				}
			}
		}