Aimbot: IsVisible/IntersectSegment crash

typedef bool(*IntersectSegment)(const IntersectQuery& Query, IntersectInfo *pInfo);
IntersectSegment pIntersectSegment;

bool __cdecl IsVisible(D3DXVECTOR3 MePos, D3DXVECTOR3 TargetPos)
{
	
	IntersectQuery iQuery;
	IntersectInfo iInfo;

	pIntersectSegment = (IntersectSegment)(*(DWORD*)(0x641480)); // Pattern Scan Address

	memset(&iQuery, 0, sizeof(iQuery));

	iQuery.m_From = MePos;
	iQuery.m_To = TargetPos;

	if (pIntersectSegment) // Redundante
	{
                // Aqui acontece o crash
		return !pIntersectSegment(iQuery, &iInfo);
	}

	return true;
}

struct IntersectInfo
{
	D3DXVECTOR3 vImpactPos;	//0x0000
	char unk_0[16];			
	cObject* hObjImpact;		//0x001C
	DWORD unk_1;			//0x0020
	DWORD unk_2;			//0x0024
	DWORD unk_3;			//0x0028
};

struct IntersectQuery
{
	D3DXVECTOR3 m_From;			//0x0000
	D3DXVECTOR3 m_To;			//0x000C
	char unknown24[12];
	unsigned int Flags;			//0x0024
	ObjectFilterFn FilterFn;			//0x0028
	void* FilterIntersectParam;		//0x002C
	ObjectFilterFn FilterIntersectFn;	//0x0030
	void* FilterParam;			//0x0034
	void* PolyFilterParam;			//0x0038
};

bool __cdecl IsVisible (D3DXVECTOR3 MePos, D3DXVECTOR3 TargetPos)
{	
	oIntersectSegment = (IntersectSegment)(0x64147D + 0x3);
	iQuery.m_From	= MePos;
	iQuery.m_To		= TargetPos;
	return !oIntersectSegment(iQuery, &iInfo);
}