Since you have no options not to install a boot loader I installed it to /dev/sda4 so it would not overwrite my current. Guess what, it installed on /dev/sda anyway. You should also ad a choice to "Dont install bootloader".
This ticket has been archived due to the age of this request, in order to keep currently present issues at the forefront for proper resolution. If this issue is still present, please reopen this ticket and provide additional details related to the request.