It looks like there is a problem with the SSL certificate, it seems to issued for the wrong hostnames (rwdb.info and www.rwdb.info).
https://www.ssllabs.com/ssltest/analyze.html?d=www.adventuregamestudio.co.uk&hideResults=on (https://www.ssllabs.com/ssltest/analyze.html?d=www.adventuregamestudio.co.uk&hideResults=on)
Hey, we've disabled the ssl due to all the issues it was causing.. :O. So please change back to using http!
However since the ssl doesn't cost anything I'll re-enable it tomorrow... I think that by removing it the https to http rewrite AGA put up no longer works.
[edit] should be OK now!