[arch-general] locked out

Hello all, After a full upgrade it seems I'm locked out :-( The system boots normally, and shows the xdm login screen. But my password is not accepted. Same in a tty, also for root. I can boot using an installation stick, mount all partitions under /mnt as during installation, and do an arch-chroot /mnt I reset my password and the root password in that environment, but that didn't help. After a normal boot I'm still locked out. Any hints to solve this will be much appreciated ! -- FA