Currently I'm not using SetVertexShader() and SetPixelShader(). I'm not sure if you need those when you are using the effect interface. Aren't these two functions called somewhere implicitly?
Apparently, I don't need "pD3dDevice_->SetFVF(simpleKnobMesh_.Mesh->GetFVF());" but removing it didn't solve the problem either.
Can you elaborate a bit on the last part? I'm not sure I understood the part with the internal reference count. Isn't it sufficient to call release() once at the end on the mesh?