After reports of users having their DVDs scratched if they changed their Xbox 360 from vertical to horizontal position, the guys over at Llamma posted a guide to 'patch' the HL360 DVD-drive.

Keep in mind that this requires opening your Xbox 360 and thus it will void your warranty.

What they did is add rubber pads on the DVD-drive case on the opposite side of the laser. Now when moving the console, which results in the disc inside moving too, the disc will hit the rubber pads first. These rubber pads will limit the inclination angle of the disc so it can't touch the metal laserblock and get scratched. It'll touch the rubber pads, but that shouldn't scratch the disc.