I have made some DVD+R backups the last 1/2 year, some which I have labeled with round ”CD” sticker labels that covers the top of the disc.

Today when I tested my collection of discs with k-probe, every disc with a label on top was damaged and unreadable with very high PO an PI. All the discs with no label on, worked fine. I have about 20 discs with label and about 25 with out label. I thought labeling on the top of the disc would make no difference to the quality of the disc, as long as the sticker is centered and symmetrical, but I guess I was wrong...

Have anybody else had similar experience after labeling their DVD or has some explanation of this strange behavior? Could it be the combination of a specific brand of labels (Multi Flip in my case) and DVD+R discs?

CD Labels can damage discs in the long term, avoid using them if your archiving them for a long time. DVD Labels won't damage the disc but DVD discs are very sensitive to inbalance, so avoid using labels if possible.
Good information on keeping cds/dvds in top condition
http://www.itl.nist.gov/div895/caref...dlingGuide.pdf

Thank you. That was a realy interesting article.

I've seen a number of reports about how the simple application of a label makes the DVD disc unreadable and un-playable. I have no direct experience with this, but i suspect that balance issues may be at least part of the problem.
Suffice it to say that NOBODY is recommending using labels on any kind on DVD's, (or on CD's either for that matter).

after reading the article RaWShadow linked to, and after reading this tread, I tried removing labels on two of my discs that did not work. After the removal of the labels, the PI and PO got about 25 times lower and the discs works perfectly again! I would never imagine that labels could cause such a problem