[pssquirrel]

Indexing baffles me as well. Sometimes a book will take more than 24 hours to index, while others take a minute or two. All my books are straight text, no fancy formatting or images or tables or whatnot. And it's not that some books get stuck and never index. If I wait long enough they do eventually finish indexing -- which leads me to second the OP's questions as to why some books take so long to index while others are quick.

I have a vague impression that indexing goes faster when I put my Kindle to sleep and plug it into AC, but this might just be my imagination. I'm also wondering if indexing goes faster if you only load a couple books at a time rather than large batches at once -- which leads me to another question: To experienced Kindle users: how many books do you consider the maximum number to load at one time? Thx!