Silverlight 4 - Dynamically Loading XAP with App.xaml as page changes the (App)Application.Current.. why?

Question

I have decided not to use the MEF/Prism approach to loading XAP files into a master Silverlight container application i am building.

I have 1 Master Silverlight application, and 2 x Applications that are going to be loaded in. My loading code is working fine, the only problem is that when i load the XAP applications in i want to load the App.xaml Application context in, as this is where i am playing an IApplication interface i have built.

 public partial class AAApp : IApplication
    {

        #region IApplication Members

        private object userContext;
        private List<Silverlight.Common.Classes.ApplicationMenuItem> menuItemsList;
        private Silverlight.Common.Controls.ApplicationMaster applicationMaster;

        public object UserContext
        {
            get
            {
                return userContext;
            }
            set{
                userContext = value;
            }
        }

        public List<Silverlight.Common.Classes.ApplicationMenuItem> MenuItemsList
        {
            get
            {
                return menuItemsList;
            }
            set
            {
                menuItemsList = value;
            }
        }

        public string ApplicationName
        {
            get { return "Application Manager"; }
        }

        public string ApplicationVersion
        {
            get { return "Version 0.1"; }
        }

        public Guid GUID
        {
            get { return new Guid("{ACD4793E-47D8-4DB7-9A32-FDB9DD6CAFD2}"); }
        }

        public bool IsFullScreen
        {
            get { return false; }
        }

        public Silverlight.Common.Controls.ApplicationMaster MasterControl
        {
            get
            {
                return applicationMaster;
            }
            set
            {
                applicationMaster = value;
            }
        }

        public bool IntialiseApp()
        {

            applicationMaster = new Silverlight.Common.Controls.ApplicationMaster();
            applicationMaster.SetApplicationContent(new MainPage());

            return true;

        }

        public bool CloseApp()
        {
            return true;
        }

        #endregion
    }

<Application xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             x:Class="Test.Application.ApplicationManager.AAApp"
             >
    <Application.Resources>

    </Application.Resources>
</Application>

The Problem i am facing is when i dynamically load AAApp in to my master silverlight Application, my (App)Application.Current is being changed to the XAP i am loadings in AAApp context.

Has anyone had this problem, and know away around this.

I use the (App)Application.Current alot to store global variables for my applications etc, and with this changing it is breaking everything.

Thanks