[TYPO3-english] Login/Logout issues

[Oliver Salzburg]

I am experiencing some very weird behavior on our site.
These are the actors in my problem:

A login page using the standard felogin, set to "Hide in menu"
A login/logout button created through TS (http://pastie.org/3340855)
An "internal" page set to "Show at any login"

Now let's have a close look at the felogin on the login page.

I checked "Display Logout Form After Successful Login"

The Redirect Modes selected are (in order):
Defined by User Record
Defined by Usergroup Record
After Login (TS or Flexform)
After Logout (TS or Flexform)
After Login Error (TS or Flexform)

"User First Supported Mode from Selection" is checked

The redirects are set up as follows:

After Successful Login Redirect to Page: Internal Page
After Failed Login Redirect to Page: Login Page
After Logout Redirect to Page: Home Page

So far so good. I assumed a setup like this was straight-forward and,
somewhat, the default use case.
Here is what happens in Firefox (after clearing "Everything"):

* I click the Login link, sending me to the Login page
* I log in and am *not* redirected. I land back on the Login page,
showing the Logout form. Why?

The second issue takes a few more steps after the first two.

* Being logged in, I click the Logout link that was created through TS.
That link directs to Home Page with ?logintype=logout, so I end up on
Home Page
* I click the Login link, sending me to the Login page
* I log in and am not redirected.
* I click the Logout link, sending me to the Home Page
* I click the Login link, sending me to the Login page, which now shows
the Logout form, even though I had just logged out. In the navigation,
I also see the link to the "internal" page.

This also doesn't seem to be a caching issue. I can still access the
internal site, which I have never visited since I cleared my browser
cache.

I can now click the Logout link as many times as I want, It won't log
me out.
When I now click the Logout button presented to me on the Login page, I
am redirected to our 404 error page.

At this point, any input is welcome.

Cheers
Oliver