Hi Carlos!
I have exactly same problem when trying to play with ChartFX demo and Silverlight addon.
My message:
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Could not load file or assembly 'ChartFX.WebForms.Base, Version=7.0.3656.30187, Culture=neutral, PublicKeyToken=a1878e2052c08dce' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
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I am about to write message to support as you suggested.
Thanks.