Annoying problem

class CXModel
{
public:

	HRESULT LoadXModel(IDirect3DDevice9 *p_iD3DDevice9);
	HRESULT RenderXModel(void);

private:

	ID3DXMesh *p_Mesh;
	LPD3DXBUFFER lpd3dxMtrlBuffer;
	DWORD dwNumMtrls;
	D3DMATERIAL9 *p_d3dMtrls9;
	LPDIRECT3DTEXTURE9 *p_iD3DMeshTextures9;

	
};

HRESULT CXModel::LoadXModel(IDirect3DDevice9 *p_iD3DDevice9)
{

	DX_ERROR_CHK(D3DXLoadMeshFromX("Meshes\\tiger.x", D3DXMESH_SYSTEMMEM,
		p_iD3DDevice9, NULL, &lpd3dxMtrlBuffer, NULL, &dwNumMtrls, &p_Mesh), "Failed to load mesh");

	D3DXMATERIAL* d3dxMaterials = (D3DXMATERIAL*)lpd3dxMtrlBuffer->GetBufferPointer();
	
	p_d3dMtrls9 = new D3DMATERIAL9[dwNumMtrls];
	p_iD3DMeshTextures9 = new LPDIRECT3DTEXTURE9[dwNumMtrls];

	for(unsigned int i = 0; i < dwNumMtrls; i++)
	{
		p_d3dMtrls9[i] = d3dxMaterials[i].MatD3D;
		p_d3dMtrls9[i].Ambient = p_d3dMtrls9[i].Diffuse;

		DX_ERROR_CHK(D3DXCreateTextureFromFile(p_iD3DDevice9, 
			"Meshes\\Tiger.bmp", &p_iD3DMeshTextures9[i]), "Failed to load texture subset");

	}
	


	return S_OK;
}

CXModel cModel;
cModel.LoadXModel(p_iD3DDevice9);

//-----------------------------INCLUDES-------------------------------


#include<d3d9.h>
#include<d3dx9.h>
#include<windows.h>
#include"Graphics.h"
#include"CXModel.h"

//-----------------------------DEFINITIONS-------------------------------


#define DX_ERROR_CHK(function, error) if(FAILED(function)){MessageBox(NULL,error, "Something.exe",MB_OK); return E_FAIL;}
#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_TEX1)

//-----------------------------GLOBALS-------------------------------



IDirect3DDevice9 *p_iD3DDevice9;
IDirect3D9 *p_iD3D9;
IDirect3DVertexBuffer9 *p_iD3DTerrainVertexBuffer9;
IDirect3DTexture9 *p_iD3DTerrainTexture9;

extern HWND hWnd;										//Defined in WinMain.cpp

float fAngle;											//Camera angle


CXModel cModel;

//---------------------------------STRUCTS/CLASSES-------------------------------


struct SCustomVertex
{
	float x,y,z; //Position

	float u,v;   //Texture coordinates

};

//-----------------------------FUNCTIONS-------------------------------


HRESULT InitializeD3D(void)
{
	p_iD3D9 = Direct3DCreate9(D3D_SDK_VERSION);

	D3DPRESENT_PARAMETERS d3dpp;
	ZeroMemory(&d3dpp, sizeof(d3dpp));
	d3dpp.Windowed = TRUE;
	d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
	d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;


	DX_ERROR_CHK(p_iD3D9->CreateDevice(D3DADAPTER_DEFAULT,D3DDEVTYPE_HAL,
		hWnd, D3DCREATE_SOFTWARE_VERTEXPROCESSING, &d3dpp, &p_iD3DDevice9), "Failed to create device");

	//-----------------------------LOAD TERRAIN OBJECTS---------------------------------------

	
	LoadTerrain();
	cModel.LoadXModel(p_iD3DDevice9);

	//-----------------------------RENDER STATES----------------------------------------------


	p_iD3DDevice9->SetRenderState(D3DRS_CULLMODE, D3DCULL_NONE);
	p_iD3DDevice9->SetRenderState(D3DRS_LIGHTING, FALSE);

	return S_OK;

}

HRESULT RenderScene(void)
{
	p_iD3DDevice9->Clear(0,NULL,D3DCLEAR_TARGET, D3DCOLOR_XRGB(0,0,255), 1.0f,0);

	//-----------------------START RENDERING SCENE---------------------------------


	p_iD3DDevice9->BeginScene();

	SetCamera();					//Set camera position and lookat point

	RenderTerrain();				//Render the base terrain


	p_iD3DDevice9->EndScene();

	//-----------------------STOP RENDERING SCENE----------------------------------


	p_iD3DDevice9->Present(NULL,NULL,NULL,NULL);

	return S_OK;

}

HRESULT LoadTerrain(void)
{
	SCustomVertex sTerrainVertices[] =
	{
		{0.0f,  0.0f, 0.0f,  0.0f, 1.0f},
		{0.0f,  0.0f, 10.0f, 0.0f, 0.0f},
		{10.0f, 0.0f, 0.0f,  1.0f, 1.0f},
		{10.0f, 0.0f, 10.0f, 1.0f, 0.0f},
	};
	
	DX_ERROR_CHK(p_iD3DDevice9->CreateVertexBuffer(4*sizeof(SCustomVertex), 0, D3DFVF_CUSTOMVERTEX,
		D3DPOOL_DEFAULT, &p_iD3DTerrainVertexBuffer9,NULL), "Failed to create terrain vertex buffer");

	VOID *p_Vertices;

	DX_ERROR_CHK(p_iD3DTerrainVertexBuffer9->Lock(0,sizeof(SCustomVertex), (VOID**)&p_Vertices, 0),
		"Failed to lock terrain vertex buffer");

	memcpy(p_Vertices, sTerrainVertices, sizeof(sTerrainVertices));

	DX_ERROR_CHK(p_iD3DTerrainVertexBuffer9->Unlock(), "Failed to unlock terrain vertex buffer");
	
	
	//----------------------------------LOAD TERRAIN TEXTURE----------------------------------

	
	D3DXCreateTextureFromFile(p_iD3DDevice9, "Textures\\Grass.bmp", &p_iD3DTerrainTexture9);

	return S_OK;
}

HRESULT RenderTerrain(void)
{
	p_iD3DDevice9->SetStreamSource(0,p_iD3DTerrainVertexBuffer9, 0, sizeof(SCustomVertex));
	p_iD3DDevice9->SetFVF(D3DFVF_CUSTOMVERTEX);
	p_iD3DDevice9->SetTexture(0, p_iD3DTerrainTexture9);
	p_iD3DDevice9->DrawPrimitive(D3DPT_TRIANGLESTRIP, 0, 2);

	return S_OK;
}

HRESULT SetCamera(void)
{
	D3DXMATRIX matView;
	D3DXMatrixLookAtLH(&matView, &D3DXVECTOR3(0.0f,2.0f,-10.0f),
		&D3DXVECTOR3(0.0f,0.0f,0.0f),
		&D3DXVECTOR3(0.0f,1.0f,0.0f));
	p_iD3DDevice9->SetTransform(D3DTS_VIEW, &matView); 

	D3DXMATRIX matProj;
	D3DXMatrixPerspectiveFovLH(&matProj, D3DX_PI/4, 1.0f, 1.0f, 100.0f);
	p_iD3DDevice9->SetTransform(D3DTS_PROJECTION, &matProj);

	return S_OK;
}


void ReleaseGraphics(void)
{
	if(p_iD3DTerrainTexture9 != NULL)
	{
		p_iD3DTerrainTexture9->Release();
		p_iD3DTerrainTexture9 = NULL;
	}
	if(p_iD3DTerrainVertexBuffer9 != NULL)
	{
		p_iD3DTerrainVertexBuffer9->Release();
		p_iD3DTerrainVertexBuffer9 = NULL;
	}
	if(p_iD3DDevice9 != NULL)
	{
		p_iD3DDevice9->Release();
		p_iD3DDevice9 = NULL;
	}
	if(p_iD3D9 != NULL)
	{
		p_iD3D9->Release();
		p_iD3D9 = NULL;
	}
}
void GetInput(void)
{

}

void SetupSkyBox(void)
{
}