#ifdef color coding in Visual Studio

[SupaFletch]

I can't get Visual Studio to reliably know which #ifdef blocks are inactive and which are active.

Anybody knows what conditions VC will be "right" and when VC will be "wrong"? It's a really handy feature when it works, but it seems like it breaks if your project is anything other than the most trivial possible project. In my case, I am conditioning a block of code based on something #defined in a global header file, not the .vcproj. It's a very, very simple situation.