claws-mail displays an empty window when 'inbox' or 'sent' is double-clicked but when 'next' is clicked it does display the next unread message and if 'ctrl +p' is entered then th message is indeed printed.

I think this problem may be connected to known problems with claws-mail under Ubuntu 12.04LTS, maybe in connection
with gdm (Gnome display manager) and Unity. Can this be confirmed even if not solved?

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: claws-mail 3.8.0-1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-35.55-generic-pae 3.2.34
Uname: Linux 3.2.0-35-generic-pae i686
ApportVersion: 2.0.1-0ubuntu17.1
Architecture: i386
Date: Sat Jan 12 15:05:32 2013
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_GB:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: claws-mail
UpgradeStatus: No upgrade log present (probably fresh install)