Where or where has my session gone?

I'm implementing the Encrypter class as described in Agile Web Development with Rails, and I'm having some problems getting it to work.

1 I need to get to the session where I've stored some related key data, but I keep getting a missing_method error when trying to retrieve what I need. 2. When using the breakpointer (I'm on Ruby 1.8.6), the model parameter [as in after_save(model)] shows undefined.

Any thoughts on what I'm missing here?

Thanks...jon