Every time when I connect to my server using SSH, comes "authentication failure" but I can login...

pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=xx.xxx.xx.xx user=root
sshd[9634]: Accepted password for root from xx.xxx.xx.xx port xxxx ssh2
And the same authentication failure comes also with other accounts than root...

Where this could occur?

Distro: Debian 5.0 (Lenny)

EDIT: No problems anymore...