Just as a follow-up.
I wanted to try the (hopefully now working) change password facilty by going to scirra.com/me which, as mentioned above, requires me to login.
Well, I Can't! It seems that I can't login to anywhere else on the site using my - correct - Username/Password combination, although because I originally set my prefs to login automatically and remember me, I login to the forum fine.
Hopefully, this will also be remedied (?!) with the forum update *fingers crossed*