I making a small 3dgame which is made as a Silverlight and XNA app, but when I draw the sprites the graphics becomes all wierd.

All my primitive types are rendered correctly, but my 3d models are just wierd

My Draw is like this when silverlight is set to draw

        private void OnDraw(object sender, GameTimerEventArgs e)
    {
        // Render the Silverlight controls using the UIElementRenderer
        elementRenderer.Render();

        // Clear the screen to a solid color
        SharedGraphicsDeviceManager.Current.GraphicsDevice.Clear(Color.CornflowerBlue);

        switch (gameState)
        {
            case GameState.ChooseStarter:
                TextBlockStatus.Text = "Find Starting Player";
                break;
            case GameState.PlaceBrick:
                TextBlockPlayer.Text = (playerTurn == PlayerTurn.PlayerOne) ? "Player One" : "Player Two";
                TextBlockState.Text = "Place Brick";
                foreach (IGraphicObject obj in _3dObjects)
                {
                    obj.Draw(cameraPosition, e);
                }
                break;
            case GameState.GiveBrick:
                TextBlockState.Text = "Give Brick";
                break;
        }

        spriteBatch.Begin();
        // Using the texture from the UIElementRenderer, 
        // draw the Silverlight controls to the screen
        spriteBatch.Draw(elementRenderer.Texture, cameraProjection, Color.White);
        spriteBatch.End();
    }

This gives me this output

If I comment the spritebatch lines out I get the correct output, except the silverlight text is of course not shown

I am not entirely sure what to look for except that zero vector I am giving to the spritebatch, but if thats the source I have no idea what I am supposed to set it as epspecially when its a 2d vector