Strong name validation fails for ElementHost

I'm trying to use the Feb CTP of WPF and I've got an element host that
I'm adding to my Windows Form, I've referenced the
WindowsFormsIntegration.dll file in the Reference Assemblies\WPF\v3.0
directory ... but when I run the application, it fails with:

Could not load file or assembly 'WindowsFormsIntegration,
Version=3.0.51116.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
or one of its dependencies. Strong name validation failed. (Exception
from HRESULT: 0x8013141A)

I strong-named both my WinForms app and my WPF control library - but
this thing is definitely failing and I'm not sure why.

Has anyone encountered this problem, and if so - how did you fix it?

Thanks,
Kevin

That's what I get for reading the documentation. One piece of MSDN
tells you to get the file from the Reference
Assemblies\Microsoft\WPF\v3.0 - thats the one that fails the strong
name.

On the other hand, if you get the WindowsFormsIntegration file from
C:\Program files\visual studio
8\common7\ide\Cider\WindowsFormsIntegration.dll - it works perfectly.

Don't you just love inconsistent documentation? I know its a CTP - but
I can't begin to count the hours I've wasted learning this stuff
because I've been sent in the wrong direction by bad docs.