Sorry to hear that, I don't think it's a dual-core system issue as the last version was developed on an Intel Core Duo 2 system. Surprised to see the level editor still works perfectly though!

I'd download it freshly and extract it to a new folder and try it again. If that fails, then I'd be keen to try and make a version of the game that works on your system. Please get in touch via the contact page if you want to help out with playtesting.