diff -ur fltk-1.3.0r9110.org/src/Fl.cxx fltk-1.3.0r9110/src/Fl.cxx

--- fltk-1.3.0r9110.org/src/Fl.cxx	2012-06-17 19:47:09.988183253 +0200

+++ fltk-1.3.0r9110/src/Fl.cxx	2012-06-17 19:47:10.127189919 +0200

@@ -1421,6 +1421,7 @@

 // hide() destroys the X window, it does not do unmap!

 #if defined(WIN32)

+extern void fl_clipboard_notify_untarget(HWND wnd);

 extern void fl_update_clipboard(void);

 #elif USE_XFT

 extern void fl_destroy_xft_draw(Window);

@@ -1471,6 +1472,8 @@

   // to destroy the window that owns the selection.

   if (GetClipboardOwner()==ip->xid)

     fl_update_clipboard();

+  // Make sure we unlink this window from the clipboard chain

+  fl_clipboard_notify_untarget(ip->xid);

   // Send a message to myself so that I'll get out of the event loop...

   PostMessage(ip->xid, WM_APP, 0, 0);

   if (ip->private_dc) fl_release_dc(ip->xid, ip->private_dc);

diff -ur fltk-1.3.0r9110.org/src/Fl_win32.cxx fltk-1.3.0r9110/src/Fl_win32.cxx

--- fltk-1.3.0r9110.org/src/Fl_win32.cxx	2012-06-17 19:47:09.987183205 +0200

+++ fltk-1.3.0r9110/src/Fl_win32.cxx	2012-06-17 19:47:19.069618739 +0200

@@ -646,6 +646,38 @@

   }

 }

+static HWND clipboard_wnd = 0;

+static HWND next_clipboard_wnd = 0;

+

+static bool initial_clipboard = true;

+

+void fl_clipboard_notify_change() {

+  // No need to do anything here...

+}

+

+void fl_clipboard_notify_target(HWND wnd) {

+  if (clipboard_wnd)

+    return;

+

+  // We get one fake WM_DRAWCLIPBOARD immediately, which we therefore

+  // need to ignore.

+  initial_clipboard = true;

+

+  clipboard_wnd = wnd;

+  next_clipboard_wnd = SetClipboardViewer(wnd);

+}

+

+void fl_clipboard_notify_untarget(HWND wnd) {

+  if (wnd != clipboard_wnd)

+    return;

+

+  ChangeClipboardChain(wnd, next_clipboard_wnd);

+  clipboard_wnd = next_clipboard_wnd = 0;

+

+  if (Fl::first_window())

+    fl_clipboard_notify_target(fl_xid(Fl::first_window()));

+}

+

 ////////////////////////////////////////////////////////////////

 char fl_is_ime = 0;

 void fl_get_codepage()

@@ -1327,6 +1359,27 @@

     Fl::handle(FL_SCREEN_CONFIGURATION_CHANGED, NULL);

     return 0;

+  case WM_CHANGECBCHAIN:

+    if ((hWnd == clipboard_wnd) &&

+        (next_clipboard_wnd == (HWND)wParam)) {

+      next_clipboard_wnd = (HWND)lParam;

+      return 0;

+    }

+    break;

+

+  case WM_DRAWCLIPBOARD:

+    // When the clipboard moves between two FLTK windows,

+    // fl_i_own_selection will temporarily be false as we are

+    // processing this message. Hence the need to use fl_find().

+    if (!initial_clipboard && !fl_find(GetClipboardOwner()))

+      fl_trigger_clipboard_notify(1);

+    initial_clipboard = false;

+

+    if (next_clipboard_wnd)

+      SendMessage(next_clipboard_wnd, WM_DRAWCLIPBOARD, wParam, lParam);

+

+    return 0;

+

   default:

     if (Fl::handle(0,0)) return 0;

     break;

@@ -1685,6 +1738,8 @@

   x->next = Fl_X::first;

   Fl_X::first = x;

+  fl_clipboard_notify_target(x->xid);

+

   x->wait_for_expose = 1;

   if (fl_show_iconic) {showit = 0; fl_show_iconic = 0;}

   if (showit) {