Are you putting labels on them or writing on them with a pen that is not made for cd writing? Either of those can affect the cd, although not usually immediately.
I am putting labels on them, but I print the labels in my printer and stick them on very, very carefully.
Also, are you using quality cds? I know the price of the 100 spindles is attractive, but I frequently get unusable cds in those.
Well, I have been using those bulk DVDs from a spindle lately. I had no idea that they might be inferior.