Session data - multiple browser problems

[sipps]

Hi all,

I have experienced problems with my sites. Background is that the site has a site_id which sits at the end of the URL which determines what products the user views amongst other things.

If a user opens one browser with one site_id and starts looking through the site it works fine. Lets say they then open a new explorer window and view the same site with a different site_id thus seeing different products.
When they go back to the first browser and view another page, the products from the second browser are shown! This is because it's taking the second site_id to the other explorer window some how.

I am used to using Apache which holds the session id of a particular browser on the web server. If you open up another browser, you get another session id so the two are completely different and nothing can travel between the two browsers, i.e. a shopping cart. If you add items to a cart in one page, they do not appear in the other browser window when you view the cart!

I think that IIS must be doing something strange here, no idea what though!

Can anyone give me any advice?

Thanks

sipps