Well, I'm stumped. You may want to contact the Devs directly, at this point. Your card is definitely one the game is supposed to support. Sorry I couldn't help resolve your issue, but at least we've made sure you were: 1) Meeting the minimum requirements (i.e. able to use OpenGL 3.2) 2) Using the right graphic processor (GTX 580M) 3) Using updated drivers 4) Regenerated your %USERPROFILE%\Documents\Gaslamp Games\Clockwork Empires\config.xml 5) Checked for deferred.inl Devs ought to be able to give you more specific pointers. Maybe you can point here to show them what you've already tried.
OK, so we've ruled out that I'm doing it wrong, so I'll post a proper.bug report when I'm done with work. Thanks for all the help.
So for anyone who is curious, I did get it working. The problem resolved itself after I deleted all local game content, then again did the thing to force the computer to use my good video card. Just verifying local files wasn't good enough, nor was just deleting local files without resetting the video card preference.
yep, the problem with steam cache check is that it will only take in account files he installed so if the game creates new config files which he doesn't know about, he will no do anything about them and keep a bad configuration.