Unfortunately, we try to cater for all browsers, but the latest release of opera has thrown a spanner in the works.
I have installed and tested opera extensively, and can confirm and replicate this problem. On this occasion, the only fix for the issue with Opera is to add the game directly to your speed dial, and access it from there as you are currently with the landing page.
The link to add to your speed dial is:
http://www.core-exiles.com/099e24da60b139021a88d3d4527268f
Adding this URI to your speed dial will allow you to login without the lockout each time, but please make sure you use the URI above EXACTLY as it appears, and do not try to bookmark any other page or section of the game.