First I'd like to say this is a great app which handles reading on a small device exactly like it should be done! Only...

after uploading a few books to the iphone I can no longer look at the authors list, doing so makes the app crash back to the home screen. I'm still able to view the full book list and put the books into new categories etc so it's not completely crippling but annoying. I'm guessing there is something wrong with the format of the author in one of the books or a problem with encoding, the books are all in english though so not the same problem as your russian users are experiencing. (Though I also get the author null error trying to add some books)