When using Emacs on desktop, the background area which does not contain characters or whitespaces is not rendered at all, instead that space gets garbled when scrolling buffer up or down or when alt-tabbing between windows, making the editor essentially unusable. I have no idea what could possibly trigger this bug. I'm using Kubuntu 14.10 and this has been and issue for at least a couple of dist-upgrades. When I start Emacs and load a file, everything still looks normal but when I start working, the screen is getting garbled. I have tried both stable and latest git versions without luck. Here is a screenshot to demonstrate the bug: http://i.imgur.com/gVh6jyd.png However, running Emacs in terminal works fine. In GNU Emacs 24.3.1 (x86_64-pc-linux-gnu, GTK+ Version 3.10.9) of 2014-06-06 on brownie, modified by Debian Windowing system distributor `The X.Org Foundation', version 11.0.11600000 System Description: Ubuntu 14.10 Configured using: `configure '--build' 'x86_64-linux-gnu' '--build' 'x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.3/site-lisp:/usr/share/emacs/site-lisp' '--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes' '--with-x-toolkit=gtk3' '--with-toolkit-scroll-bars' 'build_alias=x86_64-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro' 'CPPFLAGS=-D_FORTIFY_SOURCE=2'' Important settings: value of $LANG: en_US.UTF-8 locale-coding-system: utf-8-unix default enable-multibyte-characters: t Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Recent input: M-x r e p o r t Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Making completion list... Load-path shadows: None found. Features: (shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils help-mode easymenu time-date tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd fontset image regexp-opt fringe tabulated-list newcomment lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote make-network-process dbusbind dynamic-setting system-font-setting font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)