Why does first tree Item prelights after pressing mask key ?

[Praveen Innamuri <ajay praveen2002 gmail com>]

I am working on TreeView and noticed that the treeItem in the first
row gets prelighted (it's expander arrow goes dark) when mask key
(Ctrl/Alt/Shift), or Esc is pressed. At this moment, where ever I
click the mouse (without moving it), the first node gets expanded.
This is the undesired behavior to me as the first node gets expanded
though I click on last node.

Is there anyway to disable the first node getting prelighted (due to
key press) ? Looking at the TreeView code, it seems that the first
node is getting prelighted due to expand timeout interval (or
something else), on which I have no control from my application code.

Please suggest on disabling this behavior.
-- 
Regards,
Praveen