I have a simple window that I want to be able to move it partially off the screen. Here is the problem: I am able to move this window successfully off the left of the screen, bottom of the screen, and the right of the screen. However, when I try moving it partially off the top of the screen, it won't stay. It will pop back down. I know it's possible to do because I have seen some other applications do this...

Here is the code to my window. This is just the bare-boned window without title bar and you're able to move it by dragging on its client area

Code:
#include <windows.h>

/*  Declare Windows procedure  */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);

/*  Make the class name into a global variable  */
wchar_t szClassName[ ] = L"WindowsApp";

int WINAPI WinMain (HINSTANCE hThisInstance, HINSTANCE hPrevInstance, LPSTR lpszArgument, int nFunsterStil)
{
    HWND hwnd;               /* This is the handle for our window */
	MSG messages;            /* Here messages to the application are saved */
	ZeroMemory(&messages, sizeof(MSG));
    WNDCLASSEX wincl;        /* Data structure for the windowclass */

    /* The Window structure */
    wincl.hInstance = hThisInstance;
    wincl.lpszClassName = szClassName;
    wincl.lpfnWndProc = WindowProcedure;				/* This function is called by windows */
    wincl.style = CS_DBLCLKS;							/* Catch double-clicks */
    wincl.cbSize = sizeof (WNDCLASSEX);
    wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);		/* Use default icon and mouse-pointer */
    wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
    wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
    wincl.lpszMenuName = NULL;							/* No menu */
    wincl.cbClsExtra = 0;								/* No extra bytes after the window class */
    wincl.cbWndExtra = 0;								/* structure or the window instance */
    wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;    /* Use Windows's default color as the background*/

    /* Register the window class, and if it fails quit the program */
    if (!RegisterClassEx (&wincl))
        return 0;

    /* The class is registered */
    /* WS_EX_TOPMOST - always on top | WS_EX_NOACTIVATE - Prevent mouse input from activating the window*/
    /* WS_POPUPWINDOW - no title bar | WS_SIZEBOX - resizable */
    hwnd = CreateWindowEx (WS_EX_TOPMOST | WS_EX_NOACTIVATE, szClassName, L"App", WS_POPUPWINDOW | WS_SIZEBOX,
		CW_USEDEFAULT, CW_USEDEFAULT, 240, 120, NULL, NULL, hThisInstance, NULL);

    /* Make the window visible on the screen */
    ShowWindow (hwnd, nFunsterStil);

	while(messages.message != WM_QUIT)
	{
		// IF there is a Windows message then process it.
		if(PeekMessage(&messages, 0, 0, 0, PM_REMOVE))
		{
			TranslateMessage(&messages);
			DispatchMessage(&messages);
		}
		// ELSE, do other stuff.
		else
        	{	
				//SetWindowPos(hwnd, NULL, 0, 0, 0, 0, SWP_NOSIZE | SWP_NOMOVE | SWP_SHOWWINDOW | SWP_NOACTIVATE);
        	}
	}


    /* The program return-value is 0 - The value that PostQuitMessage() gave */
    return messages.wParam;
}


/*  This function is called by the Windows function DispatchMessage()  */

LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)                  /* handle the messages */
    {
        case WM_DESTROY:
        case WM_RBUTTONUP:
            PostQuitMessage (0);       /* send a WM_QUIT to the message queue */
            break;

		case WM_MOVING:	/* fix for a bug in windows that prevents contents of the windows from being displayed */
		case WM_SIZING:				
			{
				RECT *prc = (RECT *)lParam;
				SetWindowPos(hwnd, NULL, prc->left, prc->top, prc->right - prc->left, prc->bottom - prc->top, 0);
			}
			break;

		case WM_LBUTTONDOWN:
			SendMessage(hwnd, WM_SYSCOMMAND, SC_MOVE | 0x0002, 0);
			break;

        default:                      /* for messages that we don't deal with */
            return DefWindowProc (hwnd, message, wParam, lParam);
    }

    return 0;
}