Problem with DirectX3D initiation

[FrozenSnake]

I try to split up my DirectX stuff and GUI stuff into two classes. It has come to the part where it compiles, but this snippet return false:

if(FAILED(pd3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, hwnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &pd3dDevice)))
{
	MessageBox(NULL, "CD failed!", "Fatal error!", MB_OK);
	return false;
}

It is part of the class DxManager, I think it's the hwnd that fails. hwnd is part of the Gui class

Here is the Gui class

class Gui
{
public:
	Gui();
	virtual ~Gui();
	bool InitWindow(HINSTANCE hInstance);	
	static LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
protected:
	HINSTANCE	hInstance;
	HWND		hwnd;
private:
	int			width, height;
};

and here is the DxManager class

class DxManager : public Gui
{
public:
	DxManager();
	virtual ~DxManager();
	bool InitDirect3D();
	void StartRender();
	void StopRender();
	void CleanUp();
	void BlitToSurface();
private:
	bool fullscreen;
};

Anyone that can help me understand what is wrong?