Sessions in Tabbed Browsers

Hi.

I noticed in many applications in .NET this problem:
1. Log in a application using a tabbed (or multipage) browser like opera, netscape 7 or others.
2. Open a new page with this tabbed browser.
3. Copy the address in the browser and close the first page (the .net application). Supposedly the application has had to log out you.
4. In the new page, paste the copied address and press enter.
Result: You are login in the application!!!!!

Do you have related information to solve the problem?

Regards.

You can do the same thing with two open Internet Explorer's.

I don't see it as a problem though.... the security cookie is still active as long as the browser is open, whether its a tabbed page(Gecko) or another instance of the browser(IE).