Devexpress Xtratreelist - Problem with focusing node that is invisible

I have devexpress xtralist on window form. Now when that tree becomes full that is some nodes are not visible there on tree.

And if we scroll manually then that invisible nodes will be visible开发者_运维技巧, but problem is if we press down arrow key one by one and reaches to last visible node in the tree and then again press down arrow key and reaches to the node which is not visible then reaching to that node the application goes to crash. And there is an error that index is out of bound array.

And if we make that invisible nodes visible by doing scrolling down manually and that press down key then there is no problem. But if that nodes are invisible and if we try to focus that node then there is problem.

So I cannot understand how to solve this ? Anyone does know about this ?

What that is I have not understood yet. But problem is solved by doing this.

TreeList1.MakeNodeVisible(e.Node.Nodes.LastNode);

Now it does not crash and automatically scrolling is done when reaches to last node in the tree.

This was seen to me here: http://community.devexpress.com/forums/p/81048/304362.aspx