Just to clarify my post - I got similar issue to what Artem has described previously, I took the example, mentioned here and reviewed it a bit.
so right now, when changing the container size (and Dock property is set to Fill for the RadListView), I can see that some spacing appears between items, therefore the lowest item might become partially visible. I also noticed that more items you add - more spacing you get, which is making the number of items totally invisible.
Any ideas? thanks!