[otrs] Cannot login as root@localhost

Hi, I was a bit lazy when I set up a otrs for some colleages. Worked fine for a while but now I need some new user accounts. Unfortunally, I forgot the password of root@localhost.;-) What I did, is changing the password in the database: update system_user set pw=password('foobar') where id=1; The database has been flushed, reloaded, restarted several times since the change but I still can't login as root@localhost. I tried rcotrs restart-force as well. No effect. Any hint? Thanks! cu, Norbert