Currently Being ModeratedMar 5, 2013 8:53 PM (in response to YaowenZ)
Try resetting your iPad. Hold the on/off and home buttons together for about 10 seconds till the Apple logo appears.
No, you cannot downgrade your iBooks.
Currently Being ModeratedMar 7, 2013 3:06 PM (in response to sberman)
Thanks for the suggestion but unfortunately the problem persists for me. iBooks is unusable. There are probably a couple of dozen PDFs there and it seemed to be the last one "opened in iBooks" from webmail that triggered this.
Currently Being ModeratedMar 7, 2013 3:09 PM (in response to Giles)
The next step would be to restore your iPad using iTunes. Let it sync, then press the "Restore" button on the right of iTunes.
Currently Being ModeratedMar 7, 2013 3:17 PM (in response to sberman)
Or is there an easy way of deleting the possibly offending PDF using iTunes?
Currently Being ModeratedMar 7, 2013 3:23 PM (in response to Giles)
I'm guessing you mean iTunes on your computer, with which you sync.
Open iTunes, choose the "Books" section in the upper left, choose "PDFs" on top, find and delete the PDFs, then sync.
Currently Being ModeratedMar 7, 2013 4:05 PM (in response to sberman)
You not guessing..... you reading my mind!
Thanks for all the suggestions. Will see how I get on & report back.
Currently Being ModeratedMar 9, 2013 8:06 AM (in response to sberman)
This works for me. Actually after upgraded to 5.1.1, several problems occurred to my iPad, so I went down to the resotre mode and fresh my iPad with 5.1.1 fireware, re-installed all the software, and problem solved!