delete book leads to invalid page

[GoogleCodeExporter]

Your model / PRS+ version? sony 650 reader. latest stable prs+

What steps will reproduce the problem?
1. with a book open - press options, select delete book, confirm delete.
2. Sometimes, unpredictably - this then leads to "invalid page" message
3. pressing home will clear the message but "deleted" book thumbnail & deleted 
book notes MAY still be visible ( not always) -  a hard shut down & restart is 
needed to get device back to normal. Messing with the "deleted" thumbnail or 
the "deleted" notes causes device to hang.

expected output is that book is deleted & device returns to home page. mostly 
it does, but sometimes is goes to "invalid page" as per above description. I 
have tried removing ALL books from device & repopulating, I still get the 
occasional error as described above. but 9 out of 10 books will delete OK. 
fault does not appear linked to specific books. It is more likely a database 
pointers issue.

Original issue reported on code.google.com by [email protected] on 11 Mar 2013 at 8:31