This has been a problem for a month or two. The workaround is to cut and paste columns into a different order and then M-x sort-lines instead. But I am hoping it is a small configuration detail that can be fixed to restore functionality. emerge -p emacs [ebuild R ] app-editors/emacs-21.4-r3 emerge --info Portage 2.1-r1 (default-linux/x86/2006.0, gcc-3.3.6, glibc-2.3.6-r4, 2.6.11-gentoo-r6 i686) ================================================================= System uname: 2.6.11-gentoo-r6 i686 Intel(R) Xeon(TM) CPU 2.40GHz Gentoo Base System version 1.6.15 dev-lang/python: 2.3.5-r2, 2.4.3-r1 dev-python/pycrypto: 2.0.1-r5 dev-util/ccache: [Not Present] dev-util/confcache: [Not Present] sys-apps/sandbox: 1.2.17 sys-devel/autoconf: 2.13, 2.59-r7 sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2 sys-devel/binutils: 2.16.1-r3 sys-devel/gcc-config: 1.3.13-r2 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.11-r2 ACCEPT_KEYWORDS="x86" AUTOCLEAN="yes" CBUILD="i686-pc-linux-gnu" CFLAGS="-O2 -pipe -mcpu=i386 -fomit-frame-pointer" CHOST="i686-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/3.2/share/config /usr/kde/3.3/env /usr/kde/3.3/share/config /usr/kde/3.3/shutdown /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/lib/mozilla/defaults/pref /usr/share/X11/xkb /usr/share/config /usr/share/texmf/dvipdfm/config/ /usr/share/texmf/dvips/config/ /usr/share/texmf/tex/generic/config/ /usr/share/texmf/tex/platex/config/ /usr/share/texmf/xdvi/" CONFIG_PROTECT_MASK="/etc/env.d /etc/gconf /etc/revdep-rebuild /etc/terminfo" CXXFLAGS="-O2 -pipe -mcpu=i386 -fomit-frame-pointer" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig buildpkg distlocks fixpackages metadata-transfer sandbox sfperms strict" GENTOO_MIRRORS="http://www.ibiblio.org/pub/Linux/distributions/gentoo" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress --force --whole-file --delete --delete-after --stats --timeout=180 --exclude='/distfiles' --exclude='/local' --exclude='/packages'" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" SYNC="rsync://linux.byuh.edu/gentoo-portage" USE="x86 X alsa apache2 apm arts avi berkdb bitmap-fonts cli crypt cups dri eds emboss encode esd foomaticdb fortran gdbm gif gnome gpm gstreamer gtk gtk2 imlib ipv6 isdnlog jpeg kde libg++ libwww mad mbox mikmod motif mp3 mpeg mysql ncurses nls nptl ogg opengl openssh oss pam pcre pdflib perl php png pppd python qt qt3 qt4 quicktime readline reflection samba sdl session spell spl ssl tcltk tcpd tetex tiff truetype truetype-fonts type1-fonts udev vorbis xml xmms xorg xv zlib elibc_glibc input_devices_keyboard input_devices_mouse input_devices_evdev kernel_linux userland_GNU" Unset: CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LDFLAGS, LINGUAS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY
Do you have any customization in your ~/.emacs which could be causing problems? Try starting emacs with -q and then try to reproduce.
I started emacs with -q and reproduced the problem immediately. My .emacs file mainly sets up things for rmail.
