Ubuntu 10.10 Alpha 3 (GRUB2)
Fedora 13 (GRUB)

#/boot/grub/grub.cfg
#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
  insmod vbe
  insmod vga
  insmod video_bochs
  insmod video_cirrus
}

insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
if loadfont /usr/share/grub/unicode.pf2 ; then
  set gfxmode=640x480
  load_video
  insmod gfxterm
fi
if terminal_output gfxterm ; then true ; else
  # For backward compatibility with versions of terminal.mod that don't
  # understand terminal_output
  terminal gfxterm
fi
insmod part_msdos
insmod ext2
set root='(hd0,msdos1)'
search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
set locale_dir=($root)/boot/grub/locale
set lang=ru
insmod gettext
if [ "${recordfail}" = 1 ]; then
  set timeout=-1
else
  set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Ubuntu, with Linux 2.6.35-14-generic-pae' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	load_video
	set gfxpayload=keep
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	linux	/boot/vmlinuz-2.6.35-14-generic-pae root=UUID=935cf97e-5c17-4c29-b4b2-1ed41e0c3482 ro   quiet splash
	initrd	/boot/initrd.img-2.6.35-14-generic-pae
}
menuentry 'Ubuntu, with Linux 2.6.35-14-generic-pae (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
	recordfail
	load_video
	set gfxpayload=keep
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	echo	'Loading Linux 2.6.35-14-generic-pae ...'
	linux	/boot/vmlinuz-2.6.35-14-generic-pae root=UUID=935cf97e-5c17-4c29-b4b2-1ed41e0c3482 ro single 
	echo	'Loading initial ramdisk ...'
	initrd	/boot/initrd.img-2.6.35-14-generic-pae
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	linux16	/boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	linux16	/boot/memtest86+.bin console=ttyS0,115200n8
}
menuentry "Memory test (memtest86+, experimental multiboot)" {
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	multiboot	/boot/memtest86+_multiboot.bin
}
menuentry "Memory test (memtest86+, serial console 115200, experimental multiboot)" {
	insmod part_msdos
	insmod ext2
	set root='(hd0,msdos1)'
	search --no-floppy --fs-uuid --set 935cf97e-5c17-4c29-b4b2-1ed41e0c3482
	multiboot	/boot/memtest86+_multiboot.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows Fundamentals for Legacy PCs (on /dev/sda2)" {
	insmod part_msdos
	insmod ntfs
	set root='(hd0,msdos2)'
	search --no-floppy --fs-uuid --set b0f05f72f05f3db2
	drivemap -s (hd0) ${root}
	chainloader +1
}

### END /etc/grub.d/30_os-prober ###

##This is record i added by myself
menuentry "Fedora 13" {
set root=(hd0,6)
linux /vmlinuz-2.6.33.6-147.2.4.fc13.i686.PAE ro root=/dev/mapper/vg_mikhailpc-lv_root rd_LVM_LV=vg_mikhailpc/lv_root rd_LVM_LV=vg_mikhailpc/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us rhgb quiet rdblacklist=nouveau
initrd /initramfs-2.6.33.6-147.2.4.fc13.i686.PAE.img
}



### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###


Ubuntu don't recognize partition with fedora linux. Ideal variant would be if Ubuntu GRUB2 can find and exec GRUB from Fedora partition it would have decided any issues related to updating Fedora (Fedora upgrade the kernel to update its own GRUB config)