Luckily I have never needed storage on them for more than 2 years. We release a software CD to our remote locations once a year with things like the latest Adobe Reader, and major OS patches (field locations on slow internet connections). Anyway, they install the software soon after the CD arrives, and much after a year, all the software on the CD is obsolete anyway.
I will take your warning under advisement though and make sure not to use them for long term storage.
If I could figure out what type of disc the Verbatim 95028's are for sure, I would be very happy.