None of the tests provided in binary form run on my x64 machine. This is a widespread problem; AnyCPU projects using native 32-bit DLLs work fine on x86 machines but fail to run altogether on x64 machines.

Suggestion: since you're using 32-bit native DLLs, change the platform from AnyCPU to x86. This is the new default in VS2010 anyway. More info at http://blogs.msdn.com/rmbyers/archive/2009/06/08/anycpu-exes-are-usually...

The only other way to make the projects runnable on 64-bit versions of Windows is to ship 64-bit native binaries, and somehow pick the right ones depending on the OS (which is tricky and usually not worth the trouble).