No vibration problems with the Denon 3910 that I am aware of. I have owned both Denon 2900 (not 2910) and Denon 3910 players. My Denon 2900 vibrated like an old electric football game.
Denon DVD-2910 excessive vibration?
I was wondering if it is normal for the Denon 2910 to vibrate with authority? While playing CDs the vibration starts out strong on track 1 and then slowly diminishes with each track to nothing by the time the CD is over. I can't imagine the vibration is good for sound qualty.