C / C++ / MFC

//This is the code initializing the 2 Render Contexts
	if (!(app.hDC=GetDC(app.hWnd))                     || // Get A Device Context?
        !(PixelFormat=ChoosePixelFormat(app.hDC,&pfd)) || // Did Windows Find A Matching Pixel Format?
        !SetPixelFormat(app.hDC,PixelFormat,&pfd)      || // Able To Set The Pixel Format?
        !(app.hRC=wglCreateContext(app.hDC))           || // Able To Get A Rendering Context?
        !(app.hRC_thd=wglCreateContext(app.hDC))       || // Get the second context (for loading in parallel thread)
        !(wglShareLists(app.hRC, app.hRC_thd))         ||
        !wglMakeCurrent(app.hDC,app.hRC))		          // Try To Activate The Rendering Context
	{
		KillGLWindow();
		return false;
	}

GLuint o;                                 // display list handle
vector<v3> v,n;                           // verts, norms
vector<v2> u;                             // texcoords (UVs)
vector<face> f;                           // polygons (faces)
bool done = false;
void load_thread(void* null)              // alternate thread entry point
{
    wglMakeCurrent(app.hDC, app.hRC_thd); // works fine (seemingly)
    load_rs_shdr();                       // works fine
    load_obj("cell.obj", v,n,u,f);        // works fine
    gen_display_list(o, v, n, u, f);      // crashes my program
    done = true;
    return;
}

bool init()
{
    init_med(v3(0,0,0));                    //function to initialize opengl (enable depth, lighting, etc...)
    set_light_const(v3(0,10,0), v3(1,1,1)); //enable a light
    _beginthread(load_thread, 0, (void*)0); //function declared in process.h
    return true;
}

bool render()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    gluLookAt(0,0,5,0,0,0,0,1,0);
    if(done)
        glCallList(o);

    return true;
}

NMLISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
LVHITTESTINFO hitinfo;
hitinfo.pt = pNMListView->ptAction;
UINT uFlags;
int item = m_Err_List.HitTest(&hitinfo); 
if(item != -1)
{
  if (uFlags & LVHT_ONITEMSTATEICON)
     {
       AfxMessageBox("Click on checkbox");
     }
}