Something to do with the cache on your browser. Seems some of the newer browsers are not clearing the cache as often as they should by default (this is likely something that can be set by the user). If you can manually clear the browser cache (you can- but the specific buttons to be pressed depend on the browser you are using- what are you using?) all should be good.

Also- if you "bookmark" anything- make sure it has not "sid= " then a bunch of random characters in the email- these are called "session ids"- and as everyone has probably noticed, whenever you bookmark something from any website and the address has such a "token" attached to it- the bookmark doesn't work properly when you go to use it later. Erase everything after, and including "SID=" before bookmarking something.