Modular X with the Nvidia driver was working for me; I suspect something in either the last xorg-server or the last nvidia driver update has caused this to break. Currently, I can start up X with the 'nv' driver with no problem; using the 'nvidia' driver causes X to exit with a seg fault. I'm not sure if bug reports against the masked modular X stuff are desirable or not, so apologies if this falls under "use bleeding edge, get cut, jackass". Here's the output from the X segfault: X Window System Version 7.0.0 Release Date: 21 December 2005 X Protocol Version 11, Revision 0, Release 7.0 Build Operating System: Linux 2.6.16-gentoo-r3 x86_64 Current Operating System: Linux ankh 2.6.16-gentoo-r3 #1 SMP Sun Apr 23 22:14:38 EDT 2006 x86_64 Build Date: 23 April 2006 Before reporting problems, check http://wiki.x.org to make sure that you have the latest version. Module Loader present Markers: (--) probed, (**) from config file, (==) default setting, (++) from command line, (!!) notice, (II) informational, (WW) warning, (EE) error, (NI) not implemented, (??) unknown. (==) Log file: "/var/log/Xorg.0.log", Time: Sun Apr 23 23:03:05 2006 (==) Using config file: "/etc/X11/xorg.conf" *** If unresolved symbols were reported above, they might not *** be the reason for the server aborting. Backtrace: 0: X(xf86SigHandler+0x90) [0x481f80] 1: /lib/libc.so.6 [0x2b7b2e984440] 2: /usr/lib64/xorg/modules/drivers/nvidia_drv.so(_nv000158X+0xda) [0x2b7b302c82ba] Fatal server error: Caught signal 11. Server aborting XIO: fatal IO error 104 (Connection reset by peer) on X server ":0.0" after 0 requests (0 known processed) with 0 events remaining. and emerge --info: Portage 2.1_pre9-r3 (default-linux/amd64/2006.0, gcc-3.4.6, glibc-2.4-r1, 2.6.16-gentoo-r3 x86_64) ================================================================= System uname: 2.6.16-gentoo-r3 x86_64 AMD Athlon(tm) 64 X2 Dual Core Processor 4400+ Gentoo Base System version 1.12.0_pre18 dev-lang/python: 2.4.2-r1 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-r2 sys-devel/libtool: 1.5.22 virtual/os-headers: 2.6.11-r3 ACCEPT_KEYWORDS="amd64 ~amd64" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=k8 -mtune=k8 -O3 -fomit-frame-pointer -ftracer -fprefetch-loop-arrays -pipe -msse3" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.5/env /usr/kde/3.5/share/config /usr/kde/3.5/shutdown /usr/kde/3/share/config /usr/share/X11/xkb /usr/share/config /var/qmail/control" CONFIG_PROTECT_MASK="/etc/eselect/compiler /etc/gconf /etc/revdep-rebuild /etc/terminfo /etc/texmf/web2c /etc/env.d" CXXFLAGS="-march=k8 -mtune=k8 -O3 -fomit-frame-pointer -ftracer -fprefetch-loop-arrays -pipe -msse3" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks metadata-transfer sandbox sfperms strict" GENTOO_MIRRORS="http://gentoo.osuosl.org/ http://distro.ibiblio.org/pub/linux/distributions/gentoo/ http://www.gtlib.gatech.edu/pub/gentoo " LDFLAGS="-Wl,-O1" MAKEOPTS="-j3" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage /usr/local/xgl-coffee" SYNC="rsync://rsync.namerica.gentoo.org/gentoo-portage" USE="amd64 elibc_glibc input_devices_keyboard input_devices_mouse kernel_linux userland_GNU video_cards_nvidia video_cards_nv" Unset: ASFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LANG, LC_ALL, LINGUAS
this looks like a problem I had recently. the problem was that xorg changed it's dynamic loader in 1.0.99* versions(which are currently masked) and nvidia hasn't caught up with xorg. Use the 1.0.2 series and it works. I suggest you clean up your p.unmask file and then do a emerge -puvD world.
As Mike said: cleaning out your package.mask will help for the time being. We have to wait for nvidia to provide an updated driver.