Schema tool does not recognize existing columns

I'm using doctrine with symfony. The first schema update is working, the table exists with all defined columns.
When i now run the schema update a second time (without code changes), doctrine tries to create the columns - but they already exists:

$ php app/console doctrine:schema:update --dump-sql
CREATE SEQUENCE users_id_seq INCREMENT BY 1 MINVALUE 1 START 1;
CREATE TABLE users (id INT NOT NULL, email VARCHAR(255) NOT NULL, password VARCHAR(255) DEFAULT NULL, salt VARCHAR(255) DEFAULT NULL, realname VARCHAR(255) NOT NULL, roles TEXT NOT NULL, PRIMARY KEY(id))
$ php app/console doctrine:schema:update --force
Updating database schema...
Database schema updated successfully! "2" queries were executed
$ php app/console doctrine:schema:update --dump-sql
ALTER TABLE users ADD id INT NOT NULL;
ALTER TABLE users ADD email VARCHAR(255) NOT NULL;
ALTER TABLE users ADD password VARCHAR(255) DEFAULT NULL;
ALTER TABLE users ADD salt VARCHAR(255) DEFAULT NULL;
ALTER TABLE users ADD realname VARCHAR(255) NOT NULL;
ALTER TABLE users ADD roles TEXT NOT NULL;
ALTER TABLE users ADD PRIMARY KEY (id)

Doctrine seems to ignore existing columns.

PHPUnit segfaults because of a backslash prepended to a FQCN and has a failure in the tests run so far (see attached PHPUnit output).