I was at Top Deck Games the other day, one of the few FLGS's in South Jersey, perusing their selection of OOP D&D materials. They've always got some good old stuff in there, at very reasonable prices. In the recent past I've picked up copies of the 1st and 2nd Edition D&D core books there.
Anyway, I saw they have an old copy of Unearthed Arcana there. I picked it up, and immediately pages were slipping out. What the hell? Does every single old copy of Unearthed Arcana really have the same problem? How is that possible? Is the damned thing cursed? I'm sure some of you D&D scholars out there have the answer.
Others have posted about the many reasons Unearthed Arcana bites the big one, but for more than just the binding. I'm sure the book isn't really universally reviled, as WotC just did a reprint of it. I'm guessing, at the very least, the new verion's binding will be vastly more durable!