Why not just partition the drive like Rick suggested? I really don't think filling the drive will make matters better, since the disk size will still be the same, it will just have less free space and prolly still won't be detected right by the old game.
Partitioning however will split the disk into several smaller disks.
BTW, I would like to see this misinformation you refer to that told you to fill the disk as a way of making that game work.