Edit: boots again since Sabayon version 5.5
First of all, thank to developers for a such great distribution. I'm using it about three years. With precompiled desktop applications it's good solution for many linux users, especialy for gentoo fans.
The last my used version of Sabayon was 5.1-r1. This summer I tryed install newer one. In more little and concrete words, just wanted to notice about results...
sda1 - windows
sda2 - linux 1 bootloader
sda3 - linux 2 bootloader
sda4 - extended
sda5 - linux swap
sda6 - linux 1 root
sda7 - linux 2 root
sda8 - data
2 Sabayon versions:
sabayon 5.2 - kde and gnome
sabayon 5.3 - kde and gnome
sabayon testing - 08.11, gnome
3 On MBR (Master Boot Record) the boot manager is installed, which points to windows and two linux boot partitions.
Tryed two up-to-date boot managers and Sabayon versions mentioned above. Boot partition of those versions is not recognised as "bootable" by them.
But Sabayon 5.1-r1 and lower are recognised as "bootable".
Found that since 5.2, Sabayon started to use grub2, instead of grub legacy. Maybe that is related with "unbootable" partiton state...