NavigateToURL opening in New Window even with _Self

Question

Strange Behavior in a flash I'm working on. And I must be
doing something wrong because I can reproduce it in every flash I
create. You can check out the behavior here at a test page on my
under construction site:
http://www.i2craptor.com/
I have a menu bar at the top of the page, with the following
code:
btnHome.addEventListener(MouseEvent.CLICK,btn1ClickHandler);
function btn1ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("
http://www.i2ctech.com/"),"_Self");
btnProducts.addEventListener(MouseEvent.CLICK,btn2ClickHandler);
function btn2ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("products.html"),"_Self");
btnSupport.addEventListener(MouseEvent.CLICK,btn3ClickHandler);
function btn3ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("support.html"),"_Self");
btnResources.addEventListener(MouseEvent.CLICK,btn4ClickHandler);
function btn4ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("resources.html"),"_Self");
btnCompany.addEventListener(MouseEvent.CLICK,btn5ClickHandler);
function btn5ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("company.html"),"_Self");
btnPress.addEventListener(MouseEvent.CLICK,btn6ClickHandler);
function btn6ClickHandler(event:MouseEvent):void{
navigateToURL(new URLRequest("press.html"),"_Self");
Here is the crazy thing. If I open up a web browser and then
click the menu buttons, the buttons open the link up in a new page.
Once the NEW page opens, the menu buttons start acting as I would
expect, then opening any further links in the same web page. Is
this some internet explorer security setting? Every computer that I
have utilized (total of 5) to view the web page exhibits this same
behavior.

Answer 1

That resolved the issue. Thank you so much.