Ticking sound when playing dvd-r on new dvd players

[Marie21]

I used to have a Toshiba (which I bought 2 years ago) and never had problems playing any of my dvd-r or dvd+r. Now the Toshiba is dead and I've been trying to replace it.

I originally bought a Philips 642 but it was noisy. Made a ticking/chirping sound when playing, especially on dvd-r and dvd+r. It was a bit quieter on store bought dvds but I could still hear the chirping.

Now I replaced it with a Sony ns575p. I get no noise at all when playing store bought dvds but I get an annoying ticking sound when playing any burnt dvds.

My burnt dvds were all made using DVDX-Copy and are a few different brands (mostly cheap ones) and never gave me any problems on my old dvd player.
Has anyone else had problems with dvd player mechanisms being noisy when playing dvd-r?
Did I just end up with deffective units? (twice?)

[pinetop]

My soon to be returned Liteon 5005 ticks while playing DVD-Rs.

[samijubal]

Do you have sticky labels on the discs? They can throw them out of balance and make them noisy.

[pinetop]

I just use a sharpie.