This page features an in depth explanation with code included on how the person went about creating a GA Sudoku solver! Its also a fun read as the writer has an entertaining personality.
"I remember that I once read something from someone who tried a GA C-library on Sudoku and concluded that it was not a suitable problem. If I could solve it with my slick library, that random person on the internet, whose web page I might never find again but who may exist as far as you know, would certainly be proven wrong. A worthy cause."