Version:           1.12.3 (using KDE 4.3.3)
Compiler:          gcc-4.3.4 glibc-2.10.1-r1
OS:                Linux
Installed from:    Compiled From Sources

Behaviour:
Kmail crashes every time when trying to reply to a HTML-mail

Expected behaviour:
letting me reply to that mail

Steps to reproduce:
1) Open Kmail, open folder list of IMAP account 
2) open a certain message that contains HTML (multipart/alternative by Apple-Mail) and an attachment (since I disabled displaying of HTML content, kmail shows me the textpart of the message with the raw HTML below the text part)
3) click on REPLY button
4) Kmail crashes (100% every time)

The Crash Report of the KDE crash handler:
+++
Application: KMail (kmail), signal: Segmentation fault
#0  0xffffe424 in __kernel_vsyscall ()
#1  0xb4e1fdb6 in nanosleep () from /lib/libc.so.6
#2  0xb4e1fbce in sleep () from /lib/libc.so.6
#3  0xb75c86a8 in ?? () from /usr/lib/libkdeui.so.5
#4  0x00000000 in ?? ()
+++

further info:
- this bug does not occur with other mails of this or other IMAP accounts
- it also does not occur with other mails that contain only HTML

emerge --info:
Portage 2.1.7.16 (default/linux/x86/10.0/desktop, gcc-4.3.4, glibc-2.10.1-r1, 2.6.31-gentoo-r6 i686)
=================================================================                                   
System uname: Linux-2.6.31-gentoo-r6-i686-AMD_Duron-tm-_Processor-with-gentoo-1.12.13               
Timestamp of tree: Thu, 28 Jan 2010 20:45:01 +0000                                                  
ccache version 2.4 [enabled]                                                                        
app-shells/bash:     4.0_p35                                                                        
dev-java/java-config: 1.3.7-r1, 2.1.9-r2                                                            
dev-lang/python:     2.6.4                                                                          
dev-python/pycrypto: 2.1.0_beta1                                                                    
dev-util/ccache:     2.4-r7                                                                         
dev-util/cmake:      2.6.4-r3                                                                       
sys-apps/baselayout: 1.12.13                                                                        
sys-apps/sandbox:    1.6-r2                                                                         
sys-devel/autoconf:  2.13, 2.63-r1                                                                  
sys-devel/automake:  1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10.2                                           
sys-devel/binutils:  2.18-r3                                                                        
sys-devel/gcc-config: 1.4.1                                                                         
sys-devel/libtool:   2.2.6b                                                                         
virtual/os-headers:  2.6.27-r2                                                                      
ACCEPT_KEYWORDS="x86"                                                                               
ACCEPT_LICENSE="* -@EULA"                                                                           
CBUILD="i686-pc-linux-gnu"                                                                          
CFLAGS="-O2 -march=athlon -pipe"                                                                    
CHOST="i686-pc-linux-gnu"                                                                           
CONFIG_PROTECT="/etc /usr/share/X11/xkb /usr/share/config /var/lib/hsqldb"                          
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/ /etc/fonts/fonts.conf /etc/gconf /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo /etc/texmf/language.dat.d /etc/texmf/language.def.d /etc/texmf/updmap.d /etc/texmf/web2c /etc/udev/rules.d"                                                                                          
CXXFLAGS="-O2 -march=athlon -pipe"                                                                                    
DISTDIR="/usr/portage/distfiles"                                                                                      
FEATURES="assume-digests ccache distlocks fixpackages news parallel-fetch protect-owned sandbox sfperms strict unmerge-logs unmerge-orphans userfetch"                                                                                      
GENTOO_MIRRORS="ftp://sunsite.informatik.rwth-aachen.de/pub/Linux/gentoo ftp://ftp.snt.utwente.nl/pub/os/linux/gentoo ftp://mirror.leaseweb.com/gentoo/ ftp://gentoo.mirror.dkm.cz/pub/gentoo/ ftp://91.121.124.139/gentoo-distfiles/"      
LANG="de_DE.utf8"                                                                                                     
LDFLAGS="-Wl,-O1"
LINGUAS="en de ru he"
MAKEOPTS="-j2"
PKGDIR="/usr/portage/packages"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --stats --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage"
USE="3dnow X a52 aac acl acpi aim alsa amr berkdb bitmap-fonts bluetooth branding bzip2 cairo cdparanoia cdr cli consolekit cracklib crypt cups cxx dbus dri dts dvd dvdr dvdread eds emboss encode evo exif fam firefox flac fortran ftp gdbm gif gimp gimpprint gphoto2 gpm gstreamer gtk hal iconv icq imap ipv6 jabber jpeg jpeg2k kde ldap libnotify lirc mad mikmod mjpeg mmx mng modules mozilla mp3 mp4 mpeg msn mudflap ncurses nls nptl nptlonly offensive ogg opengl openmp pam pcre pdf perl png ppds pppd python qt qt3support qt4 quicktime readline reflection samba scanner sdl session sox spell spl ssl startup-notification svg sysfs tcpd thunar tiff timidity truetype truetype-fonts type1-fonts unicode usb v4l vcd vorbis win32codecs x264 x86 xine xml xorg xulrunner xv xvid zlib" ALSA_CARDS="ens1371" ALSA_PCM_PLUGINS="adpcm alaw asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa lfloat linear meter mmap_emul mulaw multi null plug rate route share shm softvol" APACHE2_MODULES="actions alias auth_basic authn_alias authn_anon authn_dbm authn_default authn_file authz_dbm authz_default authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs dav_lock deflate dir disk_cache env expires ext_filter file_cache filter headers include info log_config logio mem_cache mime mime_magic negotiation rewrite setenvif speling status unique_id userdir usertrack vhost_alias" ELIBC="glibc" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LINGUAS="en de ru he" RUBY_TARGETS="ruby18" SANE_BACKENDS="avision" USERLAND="GNU" VIDEO_CARDS="sis vga"
Unset:  CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, INSTALL_MASK, LC_ALL, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY