Denon DVD-2910 excessive vibration?

I just called Denon and they are not aware of a vibration problem. I was told to re-initailize the microprocessor by pressing the foward/skip and play buttons together, then while holding them down press the open/close button for about 3 seconds. The word initailize should appear in the display. He said this has worked for unexplained problems. You can also find this information on page 73 of the manual. I will try it tonight and let you know.

I have found with my 2910 that some CDs vibrate while others do not. I have been checking them by putting my hand on the side of the player as the CD spins up. Most DVDs are fine. I have not noticed degradation in the sound or video quality. I believe the vibration is due to some production discs being off centered or slightly off balance. I copied one of my music CDs with a vibration problem to a blank CD and the copy played flawlessly with no vibration. This same CD by the way caused my computer to vibrate as well. I believe this is also do to the high spin up speed of the player. It exagerates the vibration.

What bloomphoto said really makes sense to me - I have noticed the same exact thing, and the "imbalanced disc" idea crossed my mind, but for some reason I dismissed that. Like I said before, my 2910 seems to do it with sacd's, but I bet that certain other discs would too. I havn't heard or seen effects from it, but how would I know if there is a problem - maybe I'm just used to hearing the problem.

I have not had any problems with my SACDs, but if the disk is off balance, it shouldn't matter what type of disk it is.
I received a demo DVD from B&W. It made my whole cabinet shake the player was vibrating so much. I read in an online forum that other people had that problem with that demo disk. I contacted B&W and they sent me another. No vibration.
What Wahoo_Envy describes as the CD vibrating on the first few tracks and then vibrating less as the disk is playing I believe is due to the fact that the laser tracks from the inside out. As the laser moves toward the outside edge of the disk, the disk spins slower. Thus less vibration.
I also tried updating my firmware and re-initialized my player. That did not make any significant difference as far as vibration with the problematic disks.

My Denon 2200 has an extremely bad vibration with most SACD and DVD-A discs. There is no vibration with DVD or CD. The vibration gets less and less as the tracks go up, just like yours. It also runs very warm, almost hot to the touch.