Thinking I must just be using the wrong password, I changed it via the web interface, but still it refused to let me in. I then logged in as root from the console and used the "passwd loginuser" command to change it again, but still the sshd daemon refuses to accept it. I've tried restarting sshd, too, but still no-go.
The sshd log simply shows
2013:08:26-11:37:04 astaro sshd[10283]: Failed password for loginuser from 192.168.0.14 port 63896 ssh2
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