Migrations task generates wrong diff for long table names

With the attached schema, a migrations diff is generated after an initial setup of the project, although
there are no differences at all. The two models are exactly identical, the only difference is the
lenght of their table names. A diff is detected for model "Institute", but not for the one called "Institut".

The reason is in the generation of the foreign keys (Doctrine_Connection line 1624), which
generates an abbreviated foreign key name for names longer than 64 characters. This
is true in the "to" models of the migration, but not in the "from" models.