WHAT CAN RUIN CD's

  1. How NOT To Mess Up Stored CDRs!

Be careful! Even little things— including the glue on stick-on labels-
– can ruin your CDRs.

That’s one of the things your fellow readers and I found when we went
back and tested long-stored CDs. In my case, the only disks that failed
were those that I had covered with a glue-on paper label from a print-it-
yourself CD label-maker kit. Several of these labeled CDs were, in fact,
totally unreadable by every means I tried (including special data
recovery software); all the data on those CDs is just plain gone. My
best guess is the glue on these do-it-yourself labels interacted with
either the foil or the dye, rendering the CDs useless.

http://www.informationweek.com/story/showArticle.jhtml?articleID=158002631) How NOT To Mess Up Stored CDRs!