I have installed pyao under my AMD64 system and it's working with no known problems. Perhaps it should be marked as testing on AMD64?
My emerge --info just in case. Portage 2.1-r1 (default-linux/amd64/2005.1, gcc-3.4.6, glibc-2.3.6-r4, 2.6.15-mm3 x86_64) ================================================================= System uname: 2.6.15-mm3 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4400+ Gentoo Base System version 1.6.15 app-admin/eselect-compiler: [Not Present] 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-r3 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.11-r2 ACCEPT_KEYWORDS="amd64" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -march=k8 -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /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/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/terminfo" CXXFLAGS="-O2 -march=k8 -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks metadata-transfer sandbox sfperms strict" GENTOO_MIRRORS="http://mirror.datapipe.net/gentoo http://open-systems.ufl.edu/mirrors/gentoo http://gentoo.ccccom.com http://mirror.usu.edu/mirrors/gentoo/" 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://rsync.gentoo.org/gentoo-portage" USE="amd64 X aac acpi aim alsa apache2 avi berkdb bitmap-fonts cdr cli crypt cups divx4linux dlloader dri dvd dvdr dvdread eds emboss encode ffmpeg foomaticdb fortran ftp gif glut gnome gpm graphviz gstreamer gt gtk gtk2 gvim hal imagemagick imlib ipv6 isdnlog java jpeg kde lzw lzw-tiff mad mp3 mpeg musicbrainz mysql mysqli ncurses nls nptl nptlonly offensive ogg oggvorbis opengl oscar pam pcre pdflib perl png pppd python pyx qt qt3 qt4 quicktime readline reflection sdl server session spell spl ssl svg tcpd tiff truetype-fonts type1-fonts usb visual visualization vorbis xine xinelib xinerama xorg xpm 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, MAKEOPTS, PORTAGE_RSYNC_EXTRA_OPTS, PORTDIR_OVERLAY
yes it works fine... Thanks for testing.