Pressflow: Permision denied on bakery and bakery/login with D7 slave and D6 master

I am getting a permission denied both for registering (/bakery) and login (/bakery/login) on the slave site.

Looking at the code, it looks like bakery_taste_oatmeal_cookie() is returning false instead of a cookie.

I have tried applying the patch at #1546034: Registering for an account on a slave site does not work at all but I got the same result.

Login on master site works fine and creates the slave account on landing, and pulling users from master to slave works fine too. I believe I set my seetings and cookie domains properly.

The OATMEAL cookie seems right:

Name: OATMEAL
Value: Z2hv4h6k4kLWbfEss1yfiURpRhRGgibb9hbQ%2Ba....
Host: .dev.domain.es
Path: /
Expires: Fri, 18 May 2012 15:02:23
(not session cookie)
(not secure cookie)

Config on the slave

bakery_domain: ".dev.domain.es"
bakery_freshness: "3600"
bakery_help_text: "Otherwise you can contact the site administrators."
bakery_is_master: 0
bakery_key: "A"
bakery_master: "http://dev.domain.es/"
bakery_slaves: Array
(
    [0] => http://tienda7.dev.domain.es/
)

bakery_supported_fields: Array
(
    [name] => name
    [mail] => mail
    [status] => status
    [picture] => 0
    [language] => 0
    [signature] => 0
)

Config on master

bakery_is_master: 1
bakery_master: "http://dev.domain.es/"
bakery_slaves: Array
(
    [0] => http://tienda7.dev.domain.es/
)

bakery_help_text: "Otherwise you can contact the site administrators."
bakery_freshness: "3600"
bakery_key: "A"
bakery_domain: ".dev.domain.es"
bakery_supported_fields: Array
(
    [name] => name
    [mail] => mail
    [status] => status
    [picture] => 0
    [language] => 0
    [signature] => 0
    [timezone] => 0
)