They just transferred the product manager who has been working on this product for the past eight years. This means I'm the only one left who has a lot of experience with how the thing hangs together. This is not good.
If I'm understanding this correctly, it looks like someone has managed to bollix the precompiled header settings for our big compile so that every file in the compile regenerated the precompiled header file. I've fixed this now and am watching the recompilation.