Colin Watson's fixed seems to work for me ... after commenting out the lines suggested in 00_header and running update-grub it seems to have cleared it ...
GPT partition table 1) non-fs (bios_grub) 2) swap 3) btrfs (root mount)
kubuntu 12.04 3.2.0-23-generic on a AMD64 cpu
Colin Watson's fixed seems to work for me ... after commenting out the lines suggested in 00_header and running update-grub it seems to have cleared it ...
GPT partition table
1) non-fs (bios_grub)
2) swap
3) btrfs (root mount)
kubuntu 12.04 3.2.0-23-generic on a AMD64 cpu