diff -up qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage.cpp.me qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage.cpp
--- qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage.cpp.me	2009-10-02 18:26:02.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage.cpp	2009-10-02 18:27:13.000000000 +0200
@@ -144,7 +144,7 @@ QImage::Format QNativeImage::systemForma
 #elif defined(Q_WS_X11) && !defined(QT_NO_MITSHM)
 
 QNativeImage::QNativeImage(int width, int height, QImage::Format format,bool /* isTextBuffer */, QWidget *widget)
-    : xshmimg(0), xshmpm(0)
+    : xshmimg(0)
 {
     if (!X11->use_mitshm) {
         image = QImage(width, height, format);
@@ -195,11 +195,6 @@ QNativeImage::QNativeImage(int width, in
             shmctl(xshminfo.shmid, IPC_RMID, 0);
         return;
     }
-    xshmpm = XShmCreatePixmap(X11->display, DefaultRootWindow(X11->display), xshmimg->data,
-                              &xshminfo, width, height, dd);
-    if (!xshmpm) {
-        qWarning() << "QNativeImage: Unable to create shared Pixmap.";
-    }
 }
 
 
@@ -208,10 +203,6 @@ QNativeImage::~QNativeImage()
     if (!xshmimg)
         return;
 
-    if (xshmpm) {
-        XFreePixmap(X11->display, xshmpm);
-        xshmpm = 0;
-    }
     XShmDetach(X11->display, &xshminfo);
     xshmimg->data = 0;
     XDestroyImage(xshmimg);
diff -up qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage_p.h.me qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage_p.h
--- qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage_p.h.me	2009-10-02 18:33:38.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/gui/image/qnativeimage_p.h	2009-10-02 18:34:01.000000000 +0200
@@ -90,7 +90,6 @@ public:
 
 #elif defined(Q_WS_X11) && !defined(QT_NO_MITSHM)
     XImage *xshmimg;
-    Pixmap xshmpm;
     XShmSegmentInfo xshminfo;
 
 #elif defined(Q_WS_MAC)
diff -up qt-x11-opensource-src-4.5.3/src/gui/kernel/qapplication_x11.cpp.me qt-x11-opensource-src-4.5.3/src/gui/kernel/qapplication_x11.cpp
--- qt-x11-opensource-src-4.5.3/src/gui/kernel/qapplication_x11.cpp.me	2009-10-02 18:27:55.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/gui/kernel/qapplication_x11.cpp	2009-10-02 18:33:30.000000000 +0200
@@ -1959,12 +1959,9 @@ void qt_init(QApplicationPrivate *priv, 
             bool local = displayName.isEmpty() || displayName.lastIndexOf(QLatin1Char(':')) == 0;
             if (local && (qgetenv("QT_X11_NO_MITSHM").toInt() == 0)) {
                 Visual *defaultVisual = DefaultVisual(X11->display, DefaultScreen(X11->display));
-                X11->use_mitshm = mitshm_pixmaps && ((defaultVisual->red_mask == 0xff0000
-                                                      || defaultVisual->red_mask == 0xf800)
-                                                     && (defaultVisual->green_mask == 0xff00
-                                                         || defaultVisual->green_mask == 0x7e0)
-                                                     && (defaultVisual->blue_mask == 0xff
-                                                         || defaultVisual->blue_mask == 0x1f));
+                X11->use_mitshm = (defaultVisual->red_mask == 0xff0000 || defaultVisual->red_mask == 0xf800)
+                                   && (defaultVisual->green_mask == 0xff00 || defaultVisual->green_mask == 0x7e0)
+                                   && (defaultVisual->blue_mask == 0xff || defaultVisual->blue_mask == 0x1f);
             }
         }
 #endif // QT_NO_MITSHM
diff -up qt-x11-opensource-src-4.5.3/src/gui/painting/qwindowsurface_raster.cpp.me qt-x11-opensource-src-4.5.3/src/gui/painting/qwindowsurface_raster.cpp
--- qt-x11-opensource-src-4.5.3/src/gui/painting/qwindowsurface_raster.cpp.me	2009-10-02 18:34:18.000000000 +0200
+++ qt-x11-opensource-src-4.5.3/src/gui/painting/qwindowsurface_raster.cpp	2009-10-02 18:35:54.000000000 +0200
@@ -220,9 +220,16 @@ void QRasterWindowSurface::flush(QWidget
 
     QRect br = rgn.boundingRect().translated(offset);
 #ifndef QT_NO_MITSHM
-    if (d_ptr->image->xshmpm) {
-        XCopyArea(X11->display, d_ptr->image->xshmpm, widget->handle(), d_ptr->gc,
-                  br.x(), br.y(), br.width(), br.height(), wbr.x(), wbr.y());
+    if (d_ptr->image->xshmimg && (br.width() * br.height() > 65536)) {
+        const QImage &src = d->image->image;
+        br = br.intersected(src.rect());
+        // Hack to make sure we satisify the PutImage() constraints in the X server,
+        // since the doShmPutImage() route currently forces a migration to system ram.
+        wbr.setX(wbr.x() - br.x());
+        br.setX(0);
+        br.setWidth(src.width());
+        XShmPutImage(X11->display, widget->handle(), d_ptr->gc, d_ptr->image->xshmimg,
+                     br.x(), br.y(), wbr.x(), wbr.y(), br.width(), br.height(), False);
         XSync(X11->display, False);
     } else
 #endif