Be warned that a few of your CDs and DVDs may be starting to decay by now as well (if you see shadows on the disc surface it might be a good time to make a copy). I suspect it's much the same problem as Laser Rot and as such pretty unfixable for most mere mortals.
I personally reckon within another 30 years or so the only good video media from before the mid 90's will be CEDs as they're grooved not magnetic (loses magnetism) or optical (glue goes icky - "Laser Rot" and stuff)... but of course nobody really knows because they're still too young....
