diff --git a/src/chrome/content/overlay.js b/src/chrome/content/overlay.js
index ef0d805..dbe01a9 100644
--- a/src/chrome/content/overlay.js
+++ b/src/chrome/content/overlay.js
@@ -36,6 +36,7 @@ var firetrayChrome = { // each new window gets a new firetrayChrome !
    window close, a new window will create a new handler (and hence, a new tray
    icon) */
   onQuit: function(win) {
+    win.removeEventListener('close', firetrayChrome.onClose, true);
     firetray.Handler.unregisterWindow(win);
     firetray_log.info("windowsCount="+firetray.Handler.windowsCount+", visibleWindowsCount="+firetray.Handler.visibleWindowsCount);
     firetray_log.debug('Firetray UNLOADED !');
@@ -46,11 +47,12 @@ var firetrayChrome = { // each new window gets a new firetrayChrome !
    hides_on_close is set (we are not actually closing the tabs!). There is no
    use trying to set warnOnClose=false temporarily in onClose, since onClose is
    called *after* the popup */
+  // FIXME: https://bugzilla.mozilla.org/show_bug.cgi?id=827880 menubar
+  // prevents close button to fire 'close'
   onClose: function(event) {
     firetray_log.debug('Firetray CLOSE');
-    let win = event.originalTarget;
-    if (!win instanceof ChromeWindow)
-      throw new TypeError('originalTarget not a ChromeWindow');
+    if (event.originalTarget != window)
+      throw new TypeError('originalTarget not the current ChromeWindow');
 
     let hides_on_close = firetray.Utils.prefService.getBoolPref('hides_on_close');
     firetray_log.debug('hides_on_close: '+hides_on_close);
diff --git a/src/modules/FiretrayHandler.jsm b/src/modules/FiretrayHandler.jsm
index 8e8993c..0c4a59a 100644
--- a/src/modules/FiretrayHandler.jsm
+++ b/src/modules/FiretrayHandler.jsm
@@ -129,7 +129,7 @@ firetray.Handler = {
           firetray.Chat.init();
       } else {
         let platforms = FIRETRAY_CHAT_SUPPORTED_OS.join(", ");
-        log.error("Only "+platforms+" platform(s) supported at this time. Chat not loaded");
+        log.warn("Only "+platforms+" platform(s) supported at this time. Chat not loaded");
       }
     }
 
@@ -370,6 +370,20 @@ firetray.Handler = {
     }
   },
 
+  hideOnMinimizeMaybe: function(wid) {
+    let hidden = false;
+    let hides_on_minimize = firetray.Utils.prefService.getBoolPref('hides_on_minimize');
+    if (hides_on_minimize) {
+      let hides_single_window = firetray.Utils.prefService.getBoolPref('hides_single_window');
+      if (hides_single_window)
+        firetray.Handler.hideWindow(wid);
+      else
+        firetray.Handler.hideAllWindows();
+      hidden = true;
+    }
+    return hidden;
+  },
+
   showHideIcon: function() {
     if (firetray.Utils.prefService.getBoolPref('show_icon_on_hide'))
       firetray.Handler.setIconVisibility(
diff --git a/src/modules/ctypes/winnt/win32.jsm b/src/modules/ctypes/winnt/win32.jsm
index 38cb97b..a369106 100644
--- a/src/modules/ctypes/winnt/win32.jsm
+++ b/src/modules/ctypes/winnt/win32.jsm
@@ -105,6 +105,8 @@ var win32 = new function() {
   this.WM_SHOWWINDOW     = 0x0018;
   this.WM_WININICHANGE   = 0x001A;
   this.WM_SETTINGCHANGE  = this.WM_WININICHANGE;
+  this.WM_COMMAND        = 0x0111;
+  this.WM_SYSCOMMAND     = 0x0112;
   this.WM_HSCROLL        = 0x0114;
   this.WM_VSCROLL        = 0x0115;
   this.WM_MOUSEWHEEL     = 0x020A;
@@ -132,6 +134,9 @@ var win32 = new function() {
   this.WM_MOUSELAST      = 0x020D;
   this.WM_MOUSELAST      = 0x020A;
 
+  this.SC_MINIMIZE = 0xF020;
+  this.SC_CLOSE    = 0xF060;
+
   this.BITMAP = ctypes.StructType("BITMAP", [
     { "bmType": this.LONG },
     { "bmWidth": this.LONG },
diff --git a/src/modules/linux/FiretrayWindow.jsm b/src/modules/linux/FiretrayWindow.jsm
index 8ba273a..7c77713 100644
--- a/src/modules/linux/FiretrayWindow.jsm
+++ b/src/modules/linux/FiretrayWindow.jsm
@@ -555,17 +555,12 @@ firetray.Window.filterWindow = function(xev, gdkEv, data) {
     let winStates = firetray.Window.getXWindowStates(xid);
     let isHidden =  winStates & FIRETRAY_XWINDOW_HIDDEN;
     log.debug("winStates="+winStates+", isHidden="+isHidden);
-    // NOTE: Gecko 8.0 provides the 'sizemodechange' event
+    // NOTE: Gecko 8.0 provides the 'sizemodechange' event, which comes once
+    // the window is minimized. i.e. preventDefault() or returning false won't
+    // prevent the event.
     if (isHidden) {
       log.debug("GOT ICONIFIED");
-      let hides_on_minimize = firetray.Utils.prefService.getBoolPref('hides_on_minimize');
-      let hides_single_window = firetray.Utils.prefService.getBoolPref('hides_single_window');
-      if (hides_on_minimize) {
-        if (hides_single_window)
-          firetray.Handler.hideWindow(xid);
-        else
-          firetray.Handler.hideAllWindows();
-      }
+      firetray.Handler.hideOnMinimizeMaybe(xid);
     }
     break;
 
diff --git a/src/modules/winnt/FiretrayWindow.jsm b/src/modules/winnt/FiretrayWindow.jsm
index c7773af..afd9a4f 100644
--- a/src/modules/winnt/FiretrayWindow.jsm
+++ b/src/modules/winnt/FiretrayWindow.jsm
@@ -69,6 +69,16 @@ firetray.Window.wndProc = function(hWnd, uMsg, wParam, lParam) { // filterWindow
   } else if (uMsg === win32.WM_CLOSE) {
     log.debug("wndProc CALLED with WM_CLOSE");
 
+  } else if (uMsg === win32.WM_SYSCOMMAND) {
+    // FIXME: not work with window.minimize() (menubar hidden)
+    log.debug("wndProc CALLED with WM_SYSCOMMAND wParam="+wParam);
+    if (wParam === win32.SC_MINIMIZE) {
+      log.debug("GOT ICONIFIED");
+      if (firetray.Window.hideOnMinimizeMaybe(wid)) {
+        return 0;               // processed => preventDefault
+      }
+    }
+
   } else if (uMsg === win32.WM_DESTROY) {
     log.debug("wndProc CALLED with WM_DESTROY "+wid);
 
@@ -80,7 +90,7 @@ firetray.Window.wndProc = function(hWnd, uMsg, wParam, lParam) { // filterWindow
   }
 
   let procPrev = firetray.Handler.wndProcsOrig.get(wid);
-  return user32.CallWindowProcW(procPrev, hWnd, uMsg, wParam, lParam);
+  return user32.CallWindowProcW(procPrev, hWnd, uMsg, wParam, lParam); // or DefWindowProcW
 };
 
 firetray.Window.attachWndProc = function(wid, hwnd) {