My guess would be yes, the quantity of books may be a factor, although I'm not aware of a published or recommended top end limit. You try creating several collections and moving then into those to reduce the number that need to displayed at once.
On the other hand, any of those purchased books can be retrieved at any time (assuming you have a network connection), so why not delete some.
then click on Managing your books and iBookstore content then click to expand
then scroll down to Is there a limit to the number of books I can have? then click to expand for the following answer:
The number of books you can have in iBooks will vary depending on the amount of space available on your device. iBooks does not limit the number of books allowed on your bookshelf.
Also, you can go to http://www.apple.com/support/ios/ibooks/ for support.
Okay, so aving re-re-installed iBooks on my iPad I am starting to despair of ever solving this. This is what happened:
Since I last installed iBooks I have opened the app approx. four times. The first time it re-loaded with my books and I searched for the book I'm currently reading - Billy Bathgate. I read, then closed by clicking the home button.
The next two times I opened iBooks I read and then closed the ame way as above.
The fourth time I tried to open iBooks the empty bookshelf appeared and after about 10 seconds it closed.
So, if the number of books is not an issue and the books load at least once, what on earth is the problem?
So now it's time for the stupid question:
IF I have over 3,000 books (which I do)
IF I have Calibre and consequently the ability to reformat said books to .mobi (which I do)
THEN how do I get all those books onto my Kindle on iPad (which I have and contains 12 bought books)?
Apologies to all on the interweb for my noobness - I Can Has Tubes With LOLCats?