Can't actualize variable session

Hi,

I have a variable session, session[:old_controller] that I m using to
make some fancy effect on my menu.
However since recetly, I have no idea but this variable refuse to be
actualized...
I am doing a <% session[:old_controller]=@controller.controller_name
%> but at the next request, if I check the value of
session[:old_controller] it didn't change...

I have no idea why, especially since I don't think I touch anything
about session since it was working just fine...

Any idea?

Cheers,
Chewbie

I forgot to say that everything is working fine when you are loggin,
the bug occurs only when you're not...
But I have no idea what is it changing...

I finally found the answer...
My authentification module was returning a "return false" when the
user was not identified, and this seemed to block everything...
I must admit I don t understand why, if someone can explain this to me
I would really appreciate...

Thx
Chewbie