There is a way, but it's not "simple". It's to check the degradation rate of your discs, by saving the original scans as a reference, re-scan them after some time and compare the scans. You can then catch any early degradation problem. Stable discs should not show any significant increase in the first year. This is assuming you use a consistent scanner, and considering the variation you posted above, I don't think it's the case with your Toshiba...
IMO if one sticks with reputable media, it's not necessary to do this for each and every disc. Personally I scan everything, but I re-check only 1 out of 5 discs of the same cakebox. At first, I also re-checked all disc containing something precious to me, but it became far too time-consuming (I now have about 800 burnt DVDRs here, among these more than 300 are "precious"! :doh: ) so now, for these, I make two copies (or even 3) on different disc models (in case you're interested, my favorite discs are Plextor-branded 8X +R TYG02, TDK-branded 8X -R YUDENT002, Verbatim-branded 16X +R MCC004 and 8X -R MCC02RG20, TDK-branded 8X +R MBIPG101 R04 and 8X -R TTG02, Ricoh-branded 4X +R RICOHJPNR01, and very old unbranded -R TDKG02 that are 2X rated but can be overspeed up to 12X in my Benq 1650).
Now the problem is, all drives report errors differently. Will the drive that one use for the original scans still be in service in a year, in two years? I've been faced with this problem, and I bought a second unit of the same drive used for original scans, just for future scanning purposes. :rolleyes: Yeah, I know, I'm mad. :bigsmile: - but my main reason to get involved into this whole DVDR thing was to transfer a very precious VHS collection of rare movies to DVD, this explaining that.
But take great care of your discs: assuming you buy good, stable media (like Verbatim), you can yourself ruin them faster than "natural" degradation ever would! Scratches, dirt, light, high humidity, heat, all things to avoid. Oh, and NEVER drop a Taiyo Yuden or Maxell disc. They are rather fragile.
Read the MEDIA FAQ
Read Care and handling of CD and DVD (thanks to Quikee for this link )
Hi Arachne - Yeah, sometimes questions from beginners are kinda forcing comprehensive/extensive/summarized answers.
I should keep the link, I won't re-write all of this! :doh: LOL