kmail doesn't show fancy headers anymore

Binary package hint: kmail

I changed once the header view of a message to 'standard' (View/Headers/Standard headers). Since then, all newly opened messages are displayed with standard headers, and I can not change back the default to 'fancy'

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: kmail 4:4.4.6-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.35-27.48-generic 2.6.35.11
Uname: Linux 2.6.35-27-generic x86_64
NonfreeKernelModules: wl fglrx
Architecture: amd64
Date: Fri Mar 4 13:38:01 2011
InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Release amd64 (20101007)
ProcEnviron:
 LANGUAGE=
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/usr/bin/tcsh
SourcePackage: kdepim