Microsoft created a number of compatibility problems they did not bother telling people about. Whether it is a bug in Windows 8 that created the compatibility problem or a conscious decision to break something is what no one knows, at this time.
No company should be held accountable when they are blind sided in the manner Microsoft has done to many companies. It is not up to the application/driver to maintain compatibility with an operating system. If the operating system is going to be changed in such a manner it will not be backward compatible, then it is up to Microsoft to let everyone know.
In forums all over the Internet people claim Windows 7 drivers are compatible with Windows 8. Microsoft, also claims the same driver SDK can be used to create drivers for Vista, Windows 7, and Windows 8. So when a driver works with Vista and Windows 7 but does not work with Windows 8, then something is amiss.
I have read the SDK documentation and cannot find where a driver for Windows 7 should not work with Windows 8. It is quite possible to create a driver which would not work with Windows 7, and run on Windows 8, but the documentation suggests the reverse should not be possible.
All that said, Microsoft did rehash the USB driver layer in Windows 8 and they did introduce some issues into it. They have those documented. In some cases the problems cannot be worked around to get a device working. Most of it occurs at device enumeration time. Whether CH is a victim of this, I cannot say.