On Windows, when I display an email that contains a background image (4K), the CPU usage go and stay at 100% making the PC becomming very slow! That doesn't append when I use the same image as backgound in an editor window. On Mac I don't see that problem but some time the image is not displayed! Here is the stack trace where we seems to get stuck: GDI32! 77f45271() GDI32! 77f45263() nsImageWin::DrawTile(nsImageWin * const 0x03803a58, nsIRenderingContext & {...}, void * 0x04397320, int 0x00000000, int 0x00000000, const nsRect & {x=0x00000000 y=0x00000000 width=0x000005e8 height=0x00000236}) line 839 + 38 bytes nsRenderingContextImpl::DrawTile(nsRenderingContextImpl * const 0x04425b68, imgIContainer * 0x03803260, int 0x00000000, int 0x00000000, const nsRect * 0x0012f238 {x=0x00000000 y=0x00000000 width=0x00005898 height=0x0000212a}) line 967 + 43 bytes nsCSSRendering::PaintBackgroundWithSC(nsIPresContext * 0x038045c0, nsIRenderingContext & {...}, nsIFrame * 0x04450368, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, const nsStyleBackground & {...}, const nsStyleBorder & {...}, int 0x00000000, int 0x00000000, int ...) line nsCSSRendering::PaintBackground(nsIPresContext * 0x038045c0, nsIRenderingContext & {...}, nsIFrame * 0x04450368, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, const nsStyleBorder & {...}, int 0x00000000, int 0x00000000, int 0x00000000) line 2633 + 45 bytes nsHTMLContainerFrame::Paint(nsHTMLContainerFrame * const 0x04450368, nsIPresContext * 0x038045c0, nsIRenderingContext & {...}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, nsFramePaintLayer eFramePaintLayer_Underlay, unsigned int 0x00000000) line 95 + 35 bytes CanvasFrame::Paint(CanvasFrame * const 0x04450368, nsIPresContext * 0x038045c0, nsIRenderingContext & {...}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, nsFramePaintLayer eFramePaintLayer_Underlay, unsigned int 0x00000000) line 388 + 27 bytes PresShell::Paint(PresShell * const 0x04468cf4, nsIView * 0x043b1d60, nsIRenderingContext & {...}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}) line 5749 + 36 bytes nsView::Paint(nsView * const 0x043b1d60, nsIRenderingContext & {...}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, unsigned int 0x00000000, int & 0x0012f584) line 280 nsViewManager::RenderDisplayListElement(DisplayListElement2 * 0x04425e60, nsIRenderingContext & {...}) line 1181 nsViewManager::RenderViews(nsView * 0x0395bc80, nsIRenderingContext & {...}, const nsRect & {x=0x00000000 y=0x00000000 width=0x00003282 height=0x00000e01}, int & 0x00000000) line 1130 nsViewManager::Refresh(nsView * 0x0395bc80, nsIRenderingContext * 0x04425b68, nsIRegion * 0x04425c40, unsigned int 0x00000001) line 721 nsViewManager::DispatchEvent(nsViewManager * const 0x043f8650, nsGUIEvent * 0x0012f890, nsEventStatus * 0x0012f7a4) line 1722 HandleEvent(nsGUIEvent * 0x0012f890) line 83 nsWindow::DispatchEvent(nsWindow * const 0x043b1c1c, nsGUIEvent * 0x0012f890, nsEventStatus & nsEventStatus_eIgnore) line 865 + 10 bytes nsWindow::DispatchWindowEvent(nsGUIEvent * 0x0012f890, nsEventStatus & nsEventStatus_eIgnore) line 891 nsWindow::OnPaint() line 4509 + 28 bytes nsWindow::ProcessMessage(unsigned int 0x0000000f, unsigned int 0x00000000, long 0x00000000, long * 0x0012fcc8) line 3398 + 17 bytes nsWindow::WindowProc(HWND__ * 0x00610530, unsigned int 0x0000000f, unsigned int 0x00000000, long 0x00000000) line 1130 + 27 bytes USER32! 77e11b60() USER32! 77e12f29() USER32! 77e12f4f() NTDLL! 77fa032f() USER32! 77e183f1() nsAppShellService::Run(nsAppShellService * const 0x017c47c0) line 309 main1(int 0x00000002, char * * 0x00304fb0, nsISupports * 0x00000000) line 1350 + 32 bytes main(int 0x00000002, char * * 0x00304fb0) line 1698 + 37 bytes mainCRTStartup() line 338 + 17 bytes KERNEL32! 77e8d326()

*** This bug has been marked as a duplicate of 98626 ***

verified dup.