The background colour of Emacs when started in windowed mode if flawed
somewhow. Lines of text have another background than the overall editing
area, and trying to change the color via M-x set-background-color does
only affect the background color of the text lines. The same goes for
themes, even if a choose a theme with dark background this only affects
the background of the text, the rest of the editing area always stays in
a light grey. This is even the case when starting Emacs with the -Q
option. See the attached screenshot for a demonstration.

I'm using the Emacs sources checked out from the Bazaar repository just
today; my OS is Arch Linux 64-bits. Desktop environment is mostly XFCE,
with the exception for the window manager which I replaced with i3. 

Greetings,
Marvin

In GNU Emacs 24.2.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.4.4)
 of 2012-09-14 on hades
Windowing system distributor `The X.Org Foundation', version
11.0.11204000 Configured using:
 `configure '--prefix=/usr' '--sysconfdir=/etc' '--localstatedir=/var'
 '--libexecdir=/usr/lib' '--mandir=/usr/share/man' '--without-sound'
 '--with-xft' '--with-x-toolkit=gtk' 'CFLAGS=-march=x86-64
 -mtune=generic -O2 -pipe -fstack-protector --param=ssp-buffer-size=4
 -D_FORTIFY_SOURCE=2'
 'LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro''

Important settings:
  value of $LC_COLLATE: C
  value of $LANG: de_DE.utf8
  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 s e t - b a c k <tab> <return> # 0 0 0 0 F F <return> 
M-x r e p o r t - e m a <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu 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 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)