grub Error 25's after updating kernels

[sean]

Installing new kernels with yum sometimes causes an Error 25 
with grub. I can't see what's wrong with grub.conf. For 
instance, this grub.conf generates an Error 25:

# grub.conf generated by anaconda
#
#boot=/dev/hda
default=4
timeout=10
# splashimage=(hd0,0)/grub/splash.xpm.gz
# hiddenmenu
title Fedora Core (2.6.11-1.1267_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1267_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1267_FC4.img




title Fedora Core (2.6.11-1.1261_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1261_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1261_FC4.img




title Fedora Core (2.6.11-1.1258_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1258_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1258_FC4.img




title Fedora Core (2.6.11-1.1253_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1253_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1253_FC4.img


title 2.6.12-rc3
         root (hd0,0)
         kernel /vmlinuz-2.6.12-rc3 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100




title Windows 2000
         map (hd0) (hd1)
         map (hd1) (hd0)
         rootnoverify (hd1,0)
         chainloader +1
         makeactive
         boot


Thanks to knoppix, I edited it to this, which booted:

# grub.conf generated by anaconda
#
#boot=/dev/hda
default=2
timeout=10
# splashimage=(hd0,0)/grub/splash.xpm.gz
# hiddenmenu
title Fedora Core (2.6.11-1.1275_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1275_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1275_FC4.img




title Fedora Core (2.6.11-1.1267_FC4)
         root (hd0,0)
         kernel /vmlinuz-2.6.11-1.1267_FC4 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100
         initrd /initrd-2.6.11-1.1267_FC4.img



title 2.6.12-rc3
         root (hd0,0)
         kernel /vmlinuz-2.6.12-rc3 root=/dev/hda5 
video=radeonfb:1024x768-32 at 100




title Windows 2000
         map (hd0) (hd1)
         map (hd1) (hd0)
         rootnoverify (hd1,0)
         chainloader +1
         makeactive
         boot


Puzzled.

sean