Fixtures loaded in the wrong order

I can't no more load my fixtures,
it's seem that Doctrine connection->unitOfWork->buildFlushTree() screw up the Model relation ordering, because some of my fixtures are loaded to soon (and I have a constrain fail).
There is nothing strange about my fixtures / models, I even don't change anything for days (and that worked perfectly fine yesterday).

I've tried to use

doctrine http://doctrine.mirror.svn.symfony-project.com/tags/1.2.1/lib/

instead of

doctrine http://doctrine.mirror.svn.symfony-project.com/branches/1.2/lib

in my lib/vendor/symfony/plugins/sfDoctrinePlugin/lib/vendor svn:externals, and the problem disapear.

Perhaps a bug as been introduced in the 1.2 branche ?