Indeed initially the items of the carousel are not visible - you have to scroll (or click one of the scroll buttons) until the first item is brought into view.

If you want the first item brought into view once the RadCarousel is loaded, then you can use a similar code:

Actually, that would be a kind of an expected behavior since ListBox handles mouse down events on its own and this event is not passed to the RadCarouselPanel.
I am sending you a sample project illustrating how you can work around this behavior. Please take a look at it and let me know whether it corresponds to your requirements.