The site that you're going to is probably using PHP or session identifiers.
You might notice something like
"
http://www.somedomain.com/index.php?sid=029_91883_932848...." in the address
bar. Sometimes you won't see this because they use a different technique to
send the information. It's basically a way to track your movements through
the site. This is how the site figures out what you last saw, the most
visited product, and the most bought products.
To alleviate this problem you can press refresh after you get back to the
page that you were last on. This will resend the information (the computer
might ask you if you want to do this) and get your session working again. You
can also press the Down arrow next to the back button and click the link that
goes directly to that page. This simulates you typing the address into the
address bar and should not require logging in again.
