You know, SVN is very useful for this sort of thing. Not only can someone else, such as Sirbomber, spot the problem, but once they've figured out how to fix it they can commit the change rather than just post how to do it. You can then look at a "diff" to see what exactly changed.
If the game crashes, the Windows error message box should provide some crash details. Usually it at least has a crash address. It might not label it in quite those words though.