diff --git a/panda/src/display/graphicsWindowInputDevice.cxx b/panda/src/display/graphicsWindowInputDevice.cxx
index 53807e68e9..df63a2a0f3 100644
--- a/panda/src/display/graphicsWindowInputDevice.cxx
+++ b/panda/src/display/graphicsWindowInputDevice.cxx
@@ -158,6 +158,19 @@ button_down(ButtonHandle button) {
   _button_events.push_back(ButtonEvent(button, ButtonEvent::T_down));
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: GraphicsWindowInputDevice::button_resume_down
+//       Access: Public
+//  Description: Records that the indicated button was depressed
+//               earlier, and we only just detected the event after
+//               the fact.  This is mainly useful for tracking the
+//               state of modifier keys.
+////////////////////////////////////////////////////////////////////
+void GraphicsWindowInputDevice::
+button_resume_down(ButtonHandle button) {
+  _button_events.push_back(ButtonEvent(button, ButtonEvent::T_resume_down));
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: GraphicsWindowInputDevice::button_up
 //       Access: Public
diff --git a/panda/src/display/graphicsWindowInputDevice.h b/panda/src/display/graphicsWindowInputDevice.h
index 6c0c2540ac..1f1589097a 100644
--- a/panda/src/display/graphicsWindowInputDevice.h
+++ b/panda/src/display/graphicsWindowInputDevice.h
@@ -62,6 +62,7 @@ public:
   // The following interface is for the various kinds of
   // GraphicsWindows to record the data incoming on the device.
   void button_down(ButtonHandle button);
+  void button_resume_down(ButtonHandle button);
   void button_up(ButtonHandle button);
   void keystroke(int keycode);
   INLINE void set_pointer_in_window(int x, int y);
diff --git a/panda/src/dxgsg8/wdxGraphicsPipe8.h b/panda/src/dxgsg8/wdxGraphicsPipe8.h
index 3ff301baa8..9a0a13c24a 100644
--- a/panda/src/dxgsg8/wdxGraphicsPipe8.h
+++ b/panda/src/dxgsg8/wdxGraphicsPipe8.h
@@ -101,6 +101,7 @@ public:
 
 private:
   static TypeHandle _type_handle;
+
   friend class wdxGraphicsWindow8;
 };
 
diff --git a/panda/src/dxgsg8/wdxGraphicsWindow8.cxx b/panda/src/dxgsg8/wdxGraphicsWindow8.cxx
index e86d901a9e..1801ee1d58 100644
--- a/panda/src/dxgsg8/wdxGraphicsWindow8.cxx
+++ b/panda/src/dxgsg8/wdxGraphicsWindow8.cxx
@@ -137,8 +137,8 @@ wdxGraphicsWindow8::
 ////////////////////////////////////////////////////////////////////
 void wdxGraphicsWindow8::
 make_gsg() {
-  wdxGraphicsPipe8 *pipe8;
-  DCAST_INTO_V(pipe8, _pipe);
+  wdxGraphicsPipe8 *dxpipe;
+  DCAST_INTO_V(dxpipe, _pipe);
 
   nassertv(_gsg == (GraphicsStateGuardian *)NULL);
   _dxgsg = new DXGraphicsStateGuardian8(this);
@@ -164,10 +164,10 @@ make_gsg() {
   if (hFind != INVALID_HANDLE_VALUE) {
     FindClose(hFind);
     _dxgsg->scrn.bIsDX81 = true;
-    pD3D8 = (*pipe8->_Direct3DCreate8)(D3D_SDK_VERSION_8_1);
+    pD3D8 = (*dxpipe->_Direct3DCreate8)(D3D_SDK_VERSION_8_1);
   } else {
     _dxgsg->scrn.bIsDX81 = false;
-    pD3D8 = (*pipe8->_Direct3DCreate8)(D3D_SDK_VERSION_8_0);
+    pD3D8 = (*dxpipe->_Direct3DCreate8)(D3D_SDK_VERSION_8_0);
   }
 
   if (pD3D8 == NULL) {
@@ -703,8 +703,8 @@ choose_adapter(LPDIRECT3D8 pD3D8) {
 ////////////////////////////////////////////////////////////////////
 bool wdxGraphicsWindow8::
 search_for_device(LPDIRECT3D8 pD3D8, DXDeviceInfo *device_info) {
-  wdxGraphicsPipe8 *pipe8;
-  DCAST_INTO_R(pipe8, _pipe, false);
+  wdxGraphicsPipe8 *dxpipe;
+  DCAST_INTO_R(dxpipe, _pipe, false);
 
   DWORD dwRenderWidth = get_properties().get_x_size();
   DWORD dwRenderHeight = get_properties().get_y_size();
@@ -763,20 +763,20 @@ search_for_device(LPDIRECT3D8 pD3D8, DXDeviceInfo *device_info) {
     UINT IDnum;
     
     // simple linear search to match DX7 card info w/DX8 card ID
-    for (IDnum=0; IDnum < pipe8->_card_ids.size(); IDnum++) {
+    for (IDnum=0; IDnum < dxpipe->_card_ids.size(); IDnum++) {
       //      wdxdisplay8_cat.info()
-      //        << "comparing '" << pipe8->_card_ids[IDnum].Driver
+      //        << "comparing '" << dxpipe->_card_ids[IDnum].Driver
       //        << "' to '" << _dxgsg->scrn.DXDeviceID.Driver << "'\n";
-      if (//(stricmp(pipe8->_card_ids[IDnum].szDriver,device_info->szDriver)==0) &&
-         (device_info->VendorID==pipe8->_card_ids[IDnum].VendorID) &&
-         (device_info->DeviceID==pipe8->_card_ids[IDnum].DeviceID) &&
-         (device_info->hMon==pipe8->_card_ids[IDnum].hMon))
+      if (//(stricmp(dxpipe->_card_ids[IDnum].szDriver,device_info->szDriver)==0) &&
+         (device_info->VendorID==dxpipe->_card_ids[IDnum].VendorID) &&
+         (device_info->DeviceID==dxpipe->_card_ids[IDnum].DeviceID) &&
+         (device_info->hMon==dxpipe->_card_ids[IDnum].hMon))
         break;
     }
     
-    if (IDnum < pipe8->_card_ids.size()) {
-      _dxgsg->scrn.MaxAvailVidMem = pipe8->_card_ids[IDnum].MaxAvailVidMem;
-      _dxgsg->scrn.bIsLowVidMemCard = pipe8->_card_ids[IDnum].bIsLowVidMemCard;
+    if (IDnum < dxpipe->_card_ids.size()) {
+      _dxgsg->scrn.MaxAvailVidMem = dxpipe->_card_ids[IDnum].MaxAvailVidMem;
+      _dxgsg->scrn.bIsLowVidMemCard = dxpipe->_card_ids[IDnum].bIsLowVidMemCard;
     } else {
       wdxdisplay8_cat.error()
         << "Error: couldnt find a CardID match in DX7 info, assuming card is not a lowmem card\n";
diff --git a/panda/src/putil/buttonEvent.cxx b/panda/src/putil/buttonEvent.cxx
index ca5a724f7d..7a77957776 100644
--- a/panda/src/putil/buttonEvent.cxx
+++ b/panda/src/putil/buttonEvent.cxx
@@ -30,6 +30,10 @@ output(ostream &out) const {
     out << "button " << _button << " down";
     break;
 
+  case T_resume_down:
+    out << "button " << _button << " resume down";
+    break;
+
   case T_up:
     out << "button " << _button << " up";
     break;
diff --git a/panda/src/putil/buttonEvent.h b/panda/src/putil/buttonEvent.h
index 09023b4319..482099be76 100644
--- a/panda/src/putil/buttonEvent.h
+++ b/panda/src/putil/buttonEvent.h
@@ -52,8 +52,21 @@
 class EXPCL_PANDA ButtonEvent {
 public:
   enum Type {
+    // T_down and T_up represent a button changing state
+    // correspondingly.  T_resume_down is a special event that is only
+    // thrown when focus is returned to a window and a button is
+    // detected as being held down at that point; it indicates that
+    // the button should be considered down now (if it wasn't
+    // already), but it didn't just get pressed down at this moment,
+    // it was depressed some time ago.  It's mainly used for correct
+    // tracking of modifier keys like shift and control, and can be
+    // ignored for other keys.
     T_down,
+    T_resume_down,
     T_up,
+
+    // T_keystroke is a special keystroke event, and is sent along
+    // with a Unicode keycode value, not a ButtonHandle.
     T_keystroke
   };
 
@@ -69,7 +82,8 @@ public:
 
   void output(ostream &out) const;
 
-  // _button will be filled in if type is T_down or T_up.
+  // _button will be filled in if type is T_down, T_resume_down, or
+  // T_up.
   ButtonHandle _button;
 
   // _keycode will be filled in if type is T_keystroke.  It will be
diff --git a/panda/src/tform/buttonThrower.cxx b/panda/src/tform/buttonThrower.cxx
index 7576f5d9ff..8b27f0071a 100644
--- a/panda/src/tform/buttonThrower.cxx
+++ b/panda/src/tform/buttonThrower.cxx
@@ -369,6 +369,13 @@ do_transmit_data(const DataNodeTransmit &input, DataNodeTransmit &output) {
           // generations.
           _button_events->add_event(be);
         }
+
+      } else if (be._type == ButtonEvent::T_resume_down) {
+        // Button resume down.  The button was pressed at some earlier
+        // time, and the event was only just now detected.  Don't
+        // throw an event now (since we already missed it), but do
+        // make sure our modifiers are up-to-date.
+        _mods.button_down(be._button);
           
       } else if (be._type == ButtonEvent::T_up) {
         // Button up.
diff --git a/panda/src/windisplay/winGraphicsWindow.I b/panda/src/windisplay/winGraphicsWindow.I
index 335db1421e..c56b970f92 100644
--- a/panda/src/windisplay/winGraphicsWindow.I
+++ b/panda/src/windisplay/winGraphicsWindow.I
@@ -51,6 +51,20 @@ handle_keypress(ButtonHandle key, int x, int y) {
   }
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: WinGraphicsWindow::handle_keyresume
+//       Access: Private
+//  Description: Indicates we detected a key was already down when the
+//               focus is restored to the window.  Mainly useful for
+//               tracking the state of modifier keys.
+////////////////////////////////////////////////////////////////////
+INLINE void WinGraphicsWindow::
+handle_keyresume(ButtonHandle key) {
+  if (key != ButtonHandle::none()) {
+    _input_devices[0].button_resume_down(key);
+  }
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: WinGraphicsWindow::handle_keyrelease
 //       Access: Private
@@ -58,7 +72,9 @@ handle_keypress(ButtonHandle key, int x, int y) {
 ////////////////////////////////////////////////////////////////////
 INLINE void WinGraphicsWindow::
 handle_keyrelease(ButtonHandle key) {
-  _input_devices[0].button_up(key);
+  if (key != ButtonHandle::none()) {
+    _input_devices[0].button_up(key);
+  }
 }
 
 ////////////////////////////////////////////////////////////////////
diff --git a/panda/src/windisplay/winGraphicsWindow.cxx b/panda/src/windisplay/winGraphicsWindow.cxx
index 8b8ea6b1c7..3b782e1431 100644
--- a/panda/src/windisplay/winGraphicsWindow.cxx
+++ b/panda/src/windisplay/winGraphicsWindow.cxx
@@ -953,10 +953,6 @@ window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
 
   case WM_SETFOCUS: 
     {
-      POINT point;
-      GetCursorPos(&point);
-      ScreenToClient(hwnd, &point);
-
       // When we lose focus, the app may miss key-up events for keys
       // that were formerly held down (and vice-versa).  Therefore,
       // when focus is regained, compare the state of the keyboard to
@@ -976,7 +972,7 @@ window_proc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam) {
             // This key has changed state.
             if ((new_keyboard_state[i] & 0x80) != 0) {
               // The key is now held down.
-              handle_keypress(lookup_key(i), point.x, point.y);
+              handle_keyresume(lookup_key(i));
             } else {
               // The key is now released.
               handle_keyrelease(lookup_key(i));
diff --git a/panda/src/windisplay/winGraphicsWindow.h b/panda/src/windisplay/winGraphicsWindow.h
index 70ee9548c0..a25acb49a2 100644
--- a/panda/src/windisplay/winGraphicsWindow.h
+++ b/panda/src/windisplay/winGraphicsWindow.h
@@ -83,6 +83,7 @@ private:
   INLINE void handle_mouse_motion(int x, int y);
   INLINE void handle_mouse_exit(void);
   INLINE void handle_keypress(ButtonHandle key, int x, int y);
+  INLINE void handle_keyresume(ButtonHandle key);
   INLINE void handle_keyrelease(ButtonHandle key);
   ButtonHandle lookup_key(WPARAM wparam) const;
   INLINE int translate_mouse(int pos) const;