Hey there,
I'm not entirely familiar with the IE8 Session Sharing thing, but from what I gather online, it's just that IE8 preserves session across all windows and tabs of the active IE8 process, right?
Your description is much scarier. You seem to imply that there is some behavior at work where browsing to ANY URL in a given window will IMMEDIATELY REFLECT in other opened windows. I hope I got that wrong, 'cuz that's something I never heard of before and also sounds totally useless and annoying. When you have two IE8 windows open and you browse to Yahoo! in one, you don't see the other one opening Yahoo! too, do you?
I see two things here:
First, do you really have an issue? I mean, is there even a use case where a user of your app with Role A would want to use it on
the same desktop as a user with Role B, without logging out this user first and logging in instead?
If that use case does happen, and you want to allow multiple independent sessions in a single use of IE8, the solution is the same regardless of the backend solution you use (I'm assuming ASP.NET, but hey, for all I know you are using PHP): go with
cookieless sessions. This means that you don't rely on cookies for storing session states, but pass a serialized session state along with all your URLs. Almost all server-side technologies have easy ways to do this. For instance:
PHP has the session.use-trans-sid setting: http://www.php.net/manual/en/session.configuration.php#ini.session.use-trans-sidASP.NET has the sessionState tag : http://msdn.microsoft.com/en-us/library/aa479314.aspxJava EE has a cookies attribute for the Context element: http://tomcat.apache.org/tomcat-5.5-doc/config/context.html#Common_Attributesetc.
Move this discussion over to the forum for your backend technology of choice if you need assistance in setting this up and
testing this.
'HTH,