MouseOver event are missing alternately

I'm using a modified form of treeview, for the treeviewitem there is a template to show a textbox with a done button in a popup. I have used a static class to find if the mouseOver (IInputElement currentPosition = Mouse.DirectlyOver;) event on any of the other treeview item to highlight them other than the one in Popup textbox. Items are added dynamically to this treeview. I'm using MVVM model here.

The problem is that when the first item is added and is in Popup textbox , the mouseover for the entire application is somehow turned off, whi开发者_StackOverflow中文版ch is not required. But on adding the second item and leaving it in the Popup textbox, the mouseover is switched on, i.e the treeviewitems get highlighted when mouseover occurs. this happens alternately....

What is capturing this mouseover event..??

try using snoop it can tell you what events are being raised, handled. and its a cool tool as well for the wpf man (or woman:)