I wrote a custom wrapper in C# that directly call methods in the VTable and that's works (but it's really painful to write) so thanks for the suggestion.

I don't blame you for anything. You was kind enough to give me the answer i feared !What i espected by posting on this forum was that someone who have access to the Direct3D 10 source code give me the confirmation that the IUnknown implementatation on ID3D10Effect objects is flawed and if a correction is planed.

I saw your codeplex project but my goal was to  see if it is possible to write a Direct3D 10 managed library using without using C++/CLI (with C#). Today the answer seem to be NO...I also saw that the other effect's interfaces don't implement IUnknown (but i have a plan for that). I'm sad to see that even a company like Microsoft can produce ...

I'm trying to do some COM Interop with Direct3D 10 and i have a strange problem with the ID3D10Effect interface.I'm currently working with D3DX10CreateEffectFromFileW. This function take many input parameters and return an effect object implementing ID3D10Effect and errors in an object implementing ID3D10Blob.My C# declaration of this function in ...