Integration between a WPF application an a C++ rendering engine

Hi!

I have problems integrating a custom rendering engine written in C++ into a WPF application. In order to integrate this engine into the WPF app, I'm currently developing a wrapper in C++/CLI (to expose a .NET class library). I have no problems with that. When I initialize my engine (at the OpenGLInitialized event), it detects the current GL context correctly and all the GL commands invoked on the native side works as intended. But, the engine fails during its rendering operations (at the OpenGLDraw event),
asserting a GL_INVALID_OPERATION error. Im using the HiddenWindow provider, with a OpenGL 3.3 profile (the engine assumes a 3.3 core profile).

Thanks in advande for any clue regarding this problem.

Warms regards.