New build with the following changes:
http://download.calibre-ebook.com/betas/
1) Fix shift clicking in the grid view
2) Highlight books that have been marked with the temp marker plugin in the grid view
3) Remove the centering of the grid view as it was causing other problems
4) A speed up in writing changes to the database, should be noticeable when making bulk changes to large numbers of books.
Hopefully this will be the last beta build.
Thanks to all of you for your testing.