Alexandria 0.6.3 (upgraded from 0.6.2 with the package from the Ubuntu Alexandria Team PPA), Ubuntu 7.10 Gutsy. 
I ran alexandria and after clikcing around several of my libraries the books didn't show up anymore. This is part of
the debug output when I look at a library that has only one book:

D, [2008-02-23T12:39:31.196337 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: ******on_focus******
D, [2008-02-23T12:39:31.196479 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: on_focus: @library_listview
D, [2008-02-23T12:39:31.196655 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:31.196941 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: sensitive: true
D, [2008-02-23T12:39:31.197070 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: on_focus delete: true
D, [2008-02-23T12:39:34.658939 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: library_button_press_event
D, [2008-02-23T12:39:34.659320 #8893] DEBUG -- <Obj Alexandria::UI::SidePaneManager>: changed
D, [2008-02-23T12:39:34.659426 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: refresh_libraries
D, [2008-02-23T12:39:34.659510 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.660068 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: sensitize_library: smartlibrary
= false
D, [2008-02-23T12:39:34.660284 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: sensitize_library delete: true
D, [2008-02-23T12:39:34.660374 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: refresh_books
D, [2008-02-23T12:39:34.660456 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.770274 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: Running block at 12:39:34
D, [2008-02-23T12:39:34.770423 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: append Suske En Wiske 286 Flierende
Fluiter
D, [2008-02-23T12:39:34.770533 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: #<Gtk::ListStore:0xb4d2ddcc
ptr=0x8e1cd90>
D, [2008-02-23T12:39:34.770792 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: iter == 0
D, [2008-02-23T12:39:34.770915 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: fill iter 0 with book
#<Alexandria::Book:0xb4ddb724>
D, [2008-02-23T12:39:34.771919 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.776733 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: Setting icon
#<Gdk::Pixbuf:0xb502983c> for book Suske En Wiske 286 Flierende Fluiter
D, [2008-02-23T12:39:34.776943 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: cache_scaled_icon
#<Gdk::Pixbuf:0xb502983c>, 20, 25
D, [2008-02-23T12:39:34.778034 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: cache_scaled_icon
#<Gdk::Pixbuf:0xb502983c>, 69.2307692307692, 90
I, [2008-02-23T12:39:34.779597 #8893]  INFO -- <Obj Alexandria::UI::UIManager>: Full iter: #<Gdk::Pixbuf:0xb50293dc
ptr=0x89e3ac8>, #<Gdk::Pixbuf:0xb50290d0 ptr=0x89e3b00>, "Suske En Wiske 286 Flierende Fluiter",
"Suske En Wiske 286 F...", "Vandersteen Willy", "9789002217883", "Standaard Uitgeverij
NV", "2006", "Paperback", 5, "9789002217883", "", true, true, true,
""
D, [2008-02-23T12:39:34.780601 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.780806 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: #index 0 percent 0.0 fraction 0.0
D, [2008-02-23T12:39:34.782865 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: on_books_selection_changed
D, [2008-02-23T12:39:34.782984 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.783184 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: selected_library
D, [2008-02-23T12:39:34.783360 #8893] DEBUG -- <Obj Alexandria::UI::UIManager>: Selected books = []

Apparently the book is found, but the screen stays blank. Restarting Alexandria shows the books as expected. 
I have defined 8 libraries. Some still empty, some with only one book, some with ~ 30 or ~130 books. 

Date: 2008-03-27 21:47
Sender: Lennart Karssen

OK, I've found out what's happening when more than the expexted
numer of books are shown in a library.

So I have a library with 133 books and one with only one book.
When I go from the one-book library to the big one the books
get loaded (with a progress bar in the lower left corner). If
I go back to the single-book-library while the big one is still
loading the book loading doesn't stop and the newly loaded books
show up in this library.

I thought this might not be related to the original bug So I
wnated to open a new one, however while testing I noticed that
this is at the heart of this bug:

In icon view: everything stays OK as long as you let each libray
finish loading. As soon as you switch from while library to another
while the first is still loading the new library will not show
any books.
If you do the same in list view the books are shown in the wrong
library.

If you are in icon view and this happens it is solved by switching
to list view and moving to another library again (allowing it
to load completely).

Date: 2008-03-27 21:35
Sender: Lennart Karssen

Indeed, changing from icon view to list view makes the book appear
(there's only one book in this specific library that I try since
it makes it easier to spot things, other libraries contain more
books, but it happens there as well).
However, when I'm in list mode something weird happens as well.
Instead of no books I see books from other libraries, but their
cover images are not shown, only the default blue book. If I
then switch to icon view again no books are shown.

Unfortunately this does not happen reproducibly. I also had cases
where switching from icon view (no books shown) to list view
simply made the one book appear. Switching back to icon view
lets the book disappear again.

Date: 2008-03-05 16:24
Sender: Tim Malone

does changing the view mode fix this? I have this problem as
well when I'm in icon mode. switching to list mode shows the
books.