Bug#539245: Black horizontal bars hide parts of the Preferences window

Package: icedove
Version: 2.0.0.19-1
Severity: normal

Hello. I have a problem which I am afraid cannot be reproduced.
When I open the Preferences windows, there are certain tabs 
(Display-->formatting, Composition --> general......) that are divided 
into areas. Each area has a title, yet these are covered by a black 
horizontal bar, that hides the name.

I also tried LANG=C icedove to find out if it was a locale issue, yet 
the problem persists, no matter which locale (I also have es_ES.utf8 
installed, as well as a couple of ISO locales).

I tried reinstalling, with no success. I'm really sorry I cannot provide 
more input, as it is an un-reproducible (as far as I know) problem. I 
haven't found anything in google, either.

Please, look at the attached file to get an idea.

Thanks, Omar

-- System Information:
Debian Release: squeeze/sid
 APT prefers testing
 APT policy: (700, 'testing'), (600, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.26-2-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash

Versions of packages icedove depends on:
ii  debianutils            3.2               Miscellaneous utilities 
specific t
ii  fontconfig             2.6.0-4           generic font configuration 
library
ii  libatk1.0-0            1.26.0-1          The ATK accessibility toolkit
ii  libc6                  2.9-12            GNU C Library: Shared libraries
ii  libcairo2              1.8.6-2+b1        The Cairo 2D vector 
graphics libra
ii  libfontconfig1         2.6.0-4           generic font configuration 
library
ii  libfreetype6           2.3.9-4.1         FreeType 2 font engine, 
shared lib
ii  libgcc1                1:4.4.0-5         GCC support library
ii  libglib2.0-0           2.20.1-2          The GLib library of C routines
ii  libgtk2.0-0            2.16.1-2          The GTK+ graphical user 
interface
ii  libhunspell-1.2-0      1.2.8-4           spell checker and 
morphological an
ii  libjpeg62              6b-14             The Independent JPEG 
Group's JPEG
ii  libnspr4-0d            4.8-1             NetScape Portable Runtime 
Library
ii  libnss3-1d             3.12.3-1          Network Security Service 
libraries
ii  libpango1.0-0          1.24.0-3+b1       Layout and rendering of 
internatio
ii  libpng12-0             1.2.37-1          PNG library - runtime
ii  libstdc++6             4.4.0-5           The GNU Standard C++ Library v3
ii  libx11-6               2:1.2.1-1         X11 client-side library
ii  libxft2                2.1.13-3          FreeType-based font drawing 
librar
ii  libxinerama1           2:1.0.3-2         X11 Xinerama extension library
ii  libxrender1            1:0.9.4-2         X Rendering Extension 
client libra
ii  libxt6                 1:1.0.5-3         X11 toolkit intrinsics library
ii  psmisc                 22.7-1            utilities that use the proc 
file s
ii  zlib1g                 1:1.2.3.3.dfsg-13 compression library - runtime

icedove recommends no packages.

Versions of packages icedove suggests:
ii  icedove-gnome-support         2.0.0.19-1 Support for Gnome in Icedove
ii  latex-xft-fonts               0.1-8      Xft-compatible versions of 
some La
ii  libthai0                      0.1.12-1   Thai language support library

-- no debconf information