Sessions, cookies and rails 3

Hi *, my question is very simple, I must be going crazy for not being
able to do something like this …
I’ve tried setting cookies with cookies.permanent[ :foo ] (both string
and symbol) and reading it after a redirect, but both cookies and
cookies.permanent are empty. I then tried in the old way, using :value
and :expires ala rack, no luck. Considering it was superweird I’ve tried
with sessions, and using session[ :foo ] has the same result, everything
is empty.
I’ve tried basically everything, changing string to symbols, inspecting
everything, even switching from 1.8.7 to 1.9.2, cookies and sessions are
not set, no matter what.
Am I missing something obvious here ? Some kind of configuration maybe ?
I have the pragprog book but they barely mention cookies, only for
storing sessions (btw, wtf?).
Your help is very appreciated, I’m lost.

TIA,
ngw