OK, let me explain what i want to do:
I am grabbing some info on a web site, and using my AR model to create
objects, but I don’t persist them, i prefer saving them to an YAML file
(obviously, i don’t have to parse only html files all the time, with a
cache mechanism, i first look up if exists in the YAML files).
Here is the problem: I create some AR objects, and i to_yaml to a file.
Then, i just copy/paste to a fixture. The problem is that the format is
a bit different (one level deeper) and i got some error when executing
the yaml file.
Has anyone experiences on this field?
Thank you again 
Jean-Etienne