I have a Lenovo Ideapad S205, which has difficulties with GRUB2. Therefore I did a manual installation of GRUB 0.97. Will a upgrade from 11.10 to 12.04 destroy my old GRUB or will it respect the custom installation?
That depends on whether or not you removed the grub-pc package before, or just installed grub-legacy to the disk from another system ( like a rescue disk ). If not, then it will be upgraded, and overwrite grub legacy.