I'm afraid this is completely frustrating me... Last night I was happily accessing my RPi from my laptop via ssh, but today I'm getting "Permission denied, please try again." to my password, and I haven't the faintest idea why! The same (never changed) password is fine on a local console, but not over ssh.
The only thing that happened meanwhile is that this morning I thought I'd try once more to see if I could get anything useful out of the OpenELEC I also installed [I couldn't...]. While that was running, I tried to ssh in to it, but of course the host key was different, so I didn't go any further. However, when I rebooted to Raspbian, the key had apparently changed there too [?], so I deleted the key from known_hosts and started over. The key seemed to be set properly, and it connects to the Pi, but the password isn't going through.
I can't find any file that has changed in the relevant interval, except maybe the contents of /var/cache/debconf, but I don't know whether that is relevant or not. I changed it anyway when I went into raspi-config to reset my keyboard (for other reasons).
-- Pete --