There are quite a range of ip addresses listed against your username and it wouldn't neccesarily have to be a recent login. You might have used a work or Uni or ??? computer to post on the Caf and when someone else used that computer weeks or month later to go to the caf your login was still sitting in the cookies on that machine.
I take it by your present IP, you're back in HK at the moment Jacqueline. The post that started all this originated from Toronto and given the flight time between the two places it's definitely not you losing it and we can't blame alcohol (well not for the post anyway ).
The IP address the alien post came from was one of a batch in Toronto you've used before, so Wibbs' explanation seems the most likely in that you have probably logged in from a shared computer at Uni or in an internet cafe and forgotten to log off (or saved the password in the browser). Hopefully the password change will stop it, if not we could ban the IP address as no-one else has used it but this may cut you off from the Caff at one of your haunts in Canada.