If I manually add the flag it compiles and runs fine.
Portage 2.0.53 (default-linux/amd64/2005.1, gcc-3.4.4, glibc-2.3.5-r2, 2.6.14
x8
6_64)
=================================================================
System uname: 2.6.14 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4200+
Gentoo Base System version 1.6.13
dev-lang/python: 2.3.5, 2.4.2
sys-apps/sandbox: 1.2.12
sys-devel/autoconf: 2.13, 2.59-r6
sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils: 2.16.1
sys-devel/libtool: 1.5.20
virtual/os-headers: 2.6.11-r2
ACCEPT_KEYWORDS="amd64"
AUTOCLEAN="yes"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=athlon64 -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env
/usr/kde/3.4/share
/config /usr/kde/3.4/shutdown /usr/kde/3/share/config
/usr/lib/X11/xkb /usr/shar
e/config /var/qmail/control"
CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d"
CXXFLAGS="-O2 -pipe"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig ccache distcc distlocks sandbox sfperms strict"
GENTOO_MIRRORS="http://distfiles.gentoo.org
http://distro.ibiblio.org/pub/linux/
distributions/gentoo"
MAKEOPTS="-j3"
PKGDIR="/usr/portage/packages/athlon64"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/server/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="amd64 X acpi alsa apache2 audiofile avi bash-completion berkdb
bitmap-fonts
bmp bonobo bzip2 cdinstall cdparanoia cdr cjk clamav crypt cups curl
dedicated
dga directfb dri dvd dvdr dvdread eds emul-linux-x86 encode exif expat fam
fbdev
ffmpeg foomaticdb fortran gdbm gif glut glx gnustep gnutls gphoto2 gpm
gstreame
r gtk gtk2 gtkhtml guile hal iconv idn imlib ipv6 java javascript jpeg
kerberos
krb4 lcms ldap libwww lm_sensors lzw lzw-tiff mad maildir mbox mcal mhash
mime m
ng mp3 mpeg mysql ncurses nis nls nocd nptl nptlonly nsplugin offensive ogg
open
al opengl osc oss pcre pdflib perl php png posix python qt quicktime readline
ru by
scanner sdl skey soap sockets spell spl sqlite ssl szip threads tiff truetype
truetype-fonts type1 type1-fonts udev unicode usb userlocales v4l videos vorbis
xine
xinerama xml xml2 xmms xosd xpm xprint xv zlib video_cards_nvidia userland
_GNU
kernel_linux elibc_glibc"
Unset: ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS, LINGUAS
