Friends Screwy OpenGl ( His screw up not mine )

[TkTech]

A friend of mine has this opengl code, and its a wee bit buggy. Returns a sigserver fault. Anyone see any obvious errors in the line maked //<-bug?

bool initTerrain()
{
	int i;
	int x, z;
	//GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
	
	for(i = 0; i < NUM_TERRAIN; i++)
	{
		terrain[i] = new Terrain;
	}
	
	terrain[0]->SetPrefs("terrain1.bmp", 256, 256, true);
	//terrain[0]->SetPrefs("grass.bmp", 256, 256);
	
	for(i = 0; i < NUM_TERRAIN; i++)
	{
		if(!terrain[i]->Load())
			return false;
		terrain[i]->Scale(0, 20);
		terrainDL[i] = terrain[i]->CreateDL(0,0,0);
	}
	
	userPos.y = terrain[0]->GetHeight((int)userPos.x, (int)userPos.z)+5.0;
	
	for(i = 0; i < NUM_TERRAIN; i++)
		nurbs[i] = gluNewNurbsRenderer();
	
	nurbCoord = (GLfloat *)malloc(sizeof(GLfloat)*terrain[0]->GetLength()*terrain[0]->GetWidth()*3);
	for(x = 0; x < terrain[0]->GetLength(); x++)
	{
		for(z = 0; z < terrain[0]->GetWidth(); z++)
		{
			nurbCoord[x*terrain[0]->GetLength()+z*3] = x;
			nurbCoord[x*terrain[0]->GetLength()+z*3+1] = terrain[0]->GetHeight(x, z);
			nurbCoord[x*terrain[0]->GetLength()+z*3+2] = z;
		}
	}
	
	gluNurbsProperty(nurbs[0], GLU_SAMPLING_TOLERANCE, 25.0);
	gluNurbsProperty(nurbs[0], GLU_DISPLAY_MODE, GLU_FILL);
	
	glNewList(DL_NURBS_1, GL_COMPILE);
		GLfloat knots[8] = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
		glPushMatrix();
			gluBeginSurface(nurbs[0]);
			gluNurbsSurface(nurbs[0],      //<-BUG This is the line that crashes
						   8, knots, 8, knots,
						   terrain[0]->GetLength()*terrain[0]->GetWidth(),
						   3, nurbCoord,
						   4, 4, GL_MAP2_VERTEX_3);
			gluEndSurface(nurbs[0]);
		glPopMatrix();
	glEndList();
	
	return true;
	
}