To fix the lock-screen:
Code:
nano /usr/share/themes/blanco/meegotouch/sysuid/sysuid.css
Scroll down until you find
locked-orientation: "portrait"; and change it to
locked-orientation: "";.
Hold the Ctrl on-screen key (not the physical one) and press X on the keyboard. If it just types an 'x' then backspace and do it again. Press 'Y' to save, then 'Enter'. Reboot.
This makes the lock-screen orientation aware, but only just after boot. It seems there is something elsewhere locking its orientation once you have actually used any apps and from then on the lock-screen is fixed in the last orientation you used before locking it.