Using Tree Views - Node Collapse

Hope you will find time to answer my question.
I am using data from a database table to populate my treeview.
The view populates just fine. However as I move from one node to another my last node collapse, and the new node expands. I do not wish to see the last node I was on collapse when I move to a new node. There must be some property I am not setting properly. If you can point me in the right direction, it will be really appreciated.

Thanks - Diwas Adhikari.

A: for what I know it is not a property to set (but I can be wrong).. Attached is a small example about a solution.. Return