Sorry, from what I hear, the problem is far more prevelant in the more recent CD-Rs. But I'd make sure all the data on those old CDs is still intact if I were you.
I watch all my burned animes now and then, no problem up to today, but the day one of them won't work, I'll make sure to warn you

-checking: yup, burnt Rise of the Triad (rooooh, oldie

) still works

It's not even in a case

What about writable DVDs? I ask as I've backed up documents and so on onto them that I may not need now - but would like to know they're safely backed up for the future.
My take on it is that as far as you don't let your DVD take sunlight or humidity, they'll be fine.