Version 0.12.10-16 now uploaded for both Fremantle and Diablo. The changes are:

• Fixed direction for drag-scrolling in the library view
• Fixes to variable initialisation, cleanup, etc. as reported by valgrind
• Fix to support editable combo boxes (author, series, etc)
• Removed threading - this had been bolted to support the Maemo banners and progress spinner, but without ensuring thread-safe behaviour, causing lockups, errors and segfaults
• Check window is still displayed before attempting to display banner or busy spinner
• Added option allowing enabling/disabling of library scroll bar
• Added Quit option to the popup menu

The source code changes are available from here.

The removal of threading means that long-running processes (version migration, library load, book load) sometimes fail to show the busy message (the banner/box shows but there's no text) and the busy spinner is static for Diablo (for Fremantle this still works though - must be handled outside the application). Unfortunately I don't see any other way around this - the application doesn't have any support for multi-threading, and fitting it in properly afterwards means a near-total rewrite.