Flickering during scrolling in treeview if i use virtualization

Question

Hi,

If i used virtualization in treeview then i face two problems:

1. There is flickering during the scrolling which occurred randomly.

2. Sometimes my contents disappear if i scroll rapidly up and down.

If i not used virtualization then i have faced one problem that contents are not scrolled up/down during the drag operation.

Can any one help on this.