@CE
Some guy from Gramebryo released a integration example of Gamebryo2.6 and CEGUI 0.6.2 years ago on their private forum, and haven't done any update since then. According to their agreement, I think it's not public available, so that's why you never heard of it, not because of your memory
@elena7
In our project, we use Gamebryo and CEGUI, but without using the integration from Gamebryo forum. Instead, we use directly the Direct3D9Renderer provided by CEGUI, wrapped in a RenderClick of Gamebryo, and with some RenderState management code, CEGUI just renders happily with Gamebryo. Also, that enables us to follow the latest version of CEGUI nearly painlessly. You may try this way, knowing that the integration provided by Gamebryo forum is limited to DX9.