Well, I knew it was a bit of a long shot to hack the event list to show an announcement.
In a few days it will be "A new version is available" at the top of the screen, some briefly flashing text that might catch the eye and a link to the download. No doubt that will be ignored too, and people will say that they don't read text at the top of the screen. Like sticky threads in a forum, I'm always reluctant to make them sticky as it seems the best way to ensure that most people will not read them.
I've changed the new version to do a bit more subtle flashing if the user needs to go into the unlock page, and a message in there and probably a link, if they need to set an unlock code or have the wrong unlock code.
To see that they'll already need the new version. Anyway, getting the new version is a good first step.