omg... this was ... well... thats it I'm a newb!
I had to re-activate "enable session state".
How it happened :
By default, it was enabled by windows 2000 server and S by S IT needed it. As soon I installed SUS, it has removed this "enable sessoin state" and yet, S by S IT was still using the server default.
So the solution was to activate it to my folder for that Interactive training...
at last....:p