thanks but still want to know where i did wrong.
this is my fstab:
/dev/sda1 /boot ext2 defaults,noatime 1 2
/dev/sda2 none swap sw 0 0
/dev/sda3 / ext3 noatime 0 1
none /proc proc defaults 0 0
none /dev/shm tmpfs nodev,nosuid,noexec 0 0
/dev/cdroms/cdrom0 /mnt/cdrom auto user 0 0
/dev/fd0 /media/floppy auto rw,noauto,user,sync 0 0
and this is my /grub.conf:
# Which listing to boot as default. 0 is the first, 1 the second etc.
default 0
# How many seconds to wait before the default listing is booted.
timeout 30
# Nice, fat splash-image to spice things up

# Comment out if you don't have a graphics card installed
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
title=Gentoo Linux 2.6.23-r6
# Partition where the kernel image (or operating system) is located
root (hd0,0)
kernel /boot/kernel-2.6.23-gentoo-r6 root=/dev/sda3
title=Gentoo Linux 2.6.23-r6 (rescue)
# Partition where the kernel image (or operating system) is located
root (hd0,0)
kernel /boot/kernel-genkernel-X86_64-2.6.23-gentoo-r6 root=/dev/ram0 init=/linuxrc ramdisk=8192 real_root=/dev/sda3 udev
video=vesafb:mtrr:3,ywrap
initrd /boot/initramfs-genkernel-X86_64-2.6.23-gentoo-r6