Redirect problem in IE8 compatibility mode (IE7)

[eluser]wm1i[/eluser]
In fixing this IE7 problem on my site, I notice the following:

- It is a really good idea to use a rewrite rule at the server, and set the index_page in config/config.php to an empty string, as IE7 CURI seems to have a problem with seeing a file extension (index.php) followed by something that isn't a query string.

- Going between IE8 and IE7 compatibility mode will cause the md5 hash to fail on the session cookie, and if you enable checking on the user-agent, it will destroy the session, including your user-data

- If you use the database option with the Session class, your custom user data never gets to the cookie, it is fetched from the db, which would be a nice thing to document so you don't stare too long at the cookies in IE7 wondering where the data is....

- If you have a form processed by IE7, and it has multiple submit buttons, the value of ALL the submit buttons, even those not clicked, will appear in the $_POST array. So any if-then-else code looking for one particular button just became very order-dependent and fails for all except the first button.

Hope this helps someone else.