I bypass the Disk Management tool altogether for creating, deleting, or resizing partitions with the free Linux tool known as GParted. But for the DM tool not to be able to create a new one over 1mb suggests that the drive already has an existing partition on it. Windows won't see a Linux partition on it's own. Yet the DM should indicate something like an unknown partition type is present. Is this on a new or previously used drive? The worsst case would be a failing drive where the read/write heads are the cause.