I've built the Lakeview Manor and ALMOST have 100% construction completion (based upon all 8 workbenches not having anymore things to build).
Well I built the Library, Enchanter's Tower, and the Alchemy Laboratory.
I have organized my books into type, and color (one shelf for the red books, one for the green, one for the BIG books, etc). All the Skill Books (I collect them, lol. Anyone else do that?) Are on two shelves so far, and all of my other books (random Skyrim books) are on other shelves. Well I activate a bookshelf and it'll say "19 (or 14, 9,4, etc) books can be added to this shelf", but I'm like "well that can't be right, there's already 5, 6, 9, 10, etc, books on this shelf." After backing out from the menu ALL the books on the shelf disappear!!! UGH! Luckily I reloaded and all is well, but very frustrating.
If I found out more, I'll let you know. Also, some of my stuff has been falling out of Display Cases as well. Scared me when "Otar" wasn't in my case, but on the floor!