Similar problems here. Never ran a developer version - installed Mavericks last night. iBooks opens and displays my synced library correctly. When I try to open a purchased iBook, it opens briefly, then disappears. The app is still running. if I go to View -> Full Screen, it will open another desktop and I can see it, but if I try to take it out of full screen mode, the window with the book in it disappears again.
Most times, after doing this a couple of times, the app will crash and ask if I want to reopen. PDFs open fine.
Been very happy with Mavericks so far other than this.