IE and PHP sessions
The problem
Of some reason IE seems to mix up the processes when opening up different tabs or
windows through the same opened application. This way it doesn't seem to properly
keep track of which sessions belong to which processes.
The solution
Exit the IE application and start a new one. If I open up my session based website
in the first tab, it works. It also works fine after opening the HTTP AUTH website
in a second tab. But I don't know how stable this is.