To clarify our issue see the following answer I got in another newsgroup.
There have to be a solution to this serious problem. Microsoft, please
respond.
You can't, really. What's happening is that the user now has two browser
instances running in a single process. From the perspective of the server,
there is no way to tell whether the user has a single window open, or two,
or ten. Now, there are some hacks that I can think of that *might* allow
you to work around this, but the bottom-line is, you can't ever do more than
make an educated guess about what's happening at the client. Without
knowing more about your situation, I can' t really suggest alternatives, but
you may want to protect the "events" by requring that, say, an event id
variable that's in a posted form match with an event id variable that's in
session, or use some other type of verification to positively match
apples-to-apples before you make updates or changes, or use session data in
ways that may not be appropriate.
Best regards
Software Consult AS
Microsoft Certified Partner
Arnt Kvannefoss