Effective immediately, iHub is storing a cookie in memory on your machine to keep track of your account number. This is in addition to the cookies that are kept if you check the "Check this box to remember your Username/Password" box on the login page.
This cookie is different in that it resides only in memory, not on your hard drive. When you close your browser, the cookie is erased.
The simple explanation of why we're doing this is to make it possible to add webservers in the (near) future without having to also add an expensive load-balancer.
The more technical explanation is that your account info is stored in session variables right now. In a simple "round-robin" load-balancing scenario (which is what we'll use), session variables are a bad thing. They're only known to the webserver you're currently on. When you go to another page on the site and your request is served by a different webserver (which will be the case 50% of the time in a 2-server setup), the different webserver doesn't have your session variables, so it has no idea who you are and therefore treats you like you're not logged in to the site at all.
Some of you may remember the problems we had before when we added a second webserver. The problems were caused by the fact that one webserver has no idea what session variables the other webserver had stored for you.
A memory cookie is one way around this. Hidden form fields is another. Memory cookies are much easier, though. A memory cookie is available to every page of the site without every page having to have code added to pass a hidden form field to the next page.
The reason I'm doing this right now is that I'm adding a new feature to the site that'll be "sessionless" and I will eventually make all pages sessionless so that they can be handled correctly by multiple webservers.