Cannot login (5.0)

Hi!
5.0 latest bzr.
In <email address hidden> just committed.
Users can't log in with the gtk client anymore.

Please avoid this kind of regressions if possible.

Traceback:
In [2010-03-11 09:49:57,092] ERROR:web-services:[17]: File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 58, in wrapper
[2010-03-11 09:49:57,092] ERROR:web-services:[18]: return f(self, dbname, *args, **kwargs)
[2010-03-11 09:49:57,092] ERROR:web-services:[19]: File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 119, in execute
[2010-03-11 09:49:57,092] ERROR:web-services:[20]: res = pool.execute_cr(cr, uid, obj, method, *args, **kw)
[2010-03-11 09:49:57,092] ERROR:web-services:[21]: File "/usr/local/lib/python2.6/dist-packages/openerp-server/osv/osv.py", line 111, in execute_cr
[2010-03-11 09:49:57,092] ERROR:web-services:[22]: return getattr(object, method)(cr, uid, *args, **kw)
[2010-03-11 09:49:57,092] ERROR:web-services:[23]: File "/usr/local/lib/python2.6/dist-packages/openerp-server/addons/base/ir/ir_ui_menu.py", line 81, in search
[2010-03-11 09:49:57,092] ERROR:web-services:[24]: user_groups = set(self.pool.get('res.users').read(cr, 1, uid, ['groups_id'])['groups_id'])
[2010-03-11 09:49:57,093] ERROR:web-services:[25]: File "/usr/local/lib/python2.6/dist-packages/openerp-server/addons/base/res/res_user.py", line 142, in read
[2010-03-11 09:49:57,093] ERROR:web-services:[26]: if not rec.get('action_id',True):
[2010-03-11 09:49:57,093] ERROR:web-services:[27]: AttributeError: 'str' object has no attribute 'get'