Check the screws on the bottom of the machine to see if they're the culprits. On the 8600 those are the ONLY screws holding the screen to the base. If the screen is still lose. You can pop off the LCD bezel and tighten up the screws that hold the hinges to the lid. After all that and you still have a floppy screen, the hinges could be worn out or be warped due to fatigue in the aluminium.