Works for me in both of those browsers, and more. Also seems to have worked for Ruth, Statto, and at least two other people. Suggest you check your web browser for holes and try again.
The game uses sessional cookies to store state. If your firewall/proxy server or something is set to “intolerant-bastard-mode”, it may be rejecting these cookies out of sheer paranoia, which would cause the effect you’re noting. Are you running ZoneAlarm? Consider adding scatmania.org to your trusted sites list and try again. Failing that, you can always come round to The Flat and try it there.