Spork, Rails and testunit

Hi.

I’m trying to use Spork (actually spork-testunit, last git version) with
Rails 3. My setup is correct, I manage to launch Spork (through bundle
exec)
and testdrb.
But I cannot succeed to have my models reloaded.
Spork-testunit’s doc says to put the loading commands in the prefork
block,
which I did. Nobody seems to require the use of Spork#trap_method.

What is the good way to run Spork with Rails 3?

Thanks.