Why is Visual Studio 2008 always rebuilding my whole project?

Question

I have a Visual Studio project with about 60 C++ source files. I can do a build, and it completes without errors. But if I immediately hit F7 again, it always re-compiles about

Answer 1

It seems that this problem can be caused by many things, but what fixed it for me was:

1. Closing Visual Studio
2. Manually deleting all bin and obj folders (Clean doesn't seem to do the trick)
3. Opening the solution and running Clean (I'm not sure if this is necessary, but I did it just in case...)
4. Building like normal

Note: This was for a C# program in Visual Studio 2010.