I allready tried to search the anwser... I'm stuck.
I try communicating between controllers (http://onehungrymind.com/angularjs-communicating-between-controllers/).
This works fine for me.
In next step i tried to add an ajax request, which result should be send to controllers.
The request is doing his job, but unfortunately only on every second request.
AJAX-Request
var request = $.post("http://www.mydomain.com/search.php", { data: "" });
    request.done(function( data ) {
        sharedService.prepForBroadcast(data);
    });
};
What is going wrong with this?
JAVASCRIPT
var myModule = angular.module('myModule', []);
myModule.factory('mySharedService', function($rootScope) {
    var sharedService = {};
    sharedService.message = '';
    sharedService.prepForBroadcast = function(msg) {
        this.message = msg;
        this.broadcastItem();
    };
    sharedService.broadcastItem = function() {
        $rootScope.$broadcast('handleBroadcast');
    };
    return sharedService;
});
function Controller($scope, sharedService) {
    $scope.handleClick = function() {
        var request = $.post("http://www.mydomain.com/search.php", { data: "" });
        request.done(function( data ) {
            sharedService.prepForBroadcast(data);
        });
    };
    $scope.$on('handleBroadcast', function() {
        $scope.message = 'zero: ' + sharedService.message;
    });
}
function ControllerOne($scope, sharedService) {
    $scope.$on('handleBroadcast', function() {
        $scope.message = 'ONE: ' + sharedService.message;
    });        
}
function ControllerTwo($scope, sharedService) {
    $scope.$on('handleBroadcast', function() {
        $scope.message = 'TWO: ' + sharedService.message;
    });
}
Controller.$inject = ['$scope', 'mySharedService'];        
ControllerOne.$inject = ['$scope', 'mySharedService'];
ControllerTwo.$inject = ['$scope', 'mySharedService'];
HTML
<script type='text/javascript' src="http://code.angularjs.org/angular-1.0.0rc9.js"></script>
<script type='text/javascript' src='https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js'></script>
<body ng-app="myModule">
    <div ng-controller="Controller">
        <button ng-click="handleClick();">read json</button>
    </div>
    <div ng-controller="ControllerOne">
        <input ng-model="message" >
    </div>
    <div ng-controller="ControllerTwo">
        <input ng-model="message" >
    </div>
Thank you.