Comment 7 for bug 1084255

It would appear that calibre benefits from the discontinued 01_workaround_qt_overlay_crash.patch which was being applied when using cdbs but not currently though the patch is still in debian/patches

Test case with updated raring:
get current overlay-scrollbar source
apply the 01_workaround_qt_overlay_crash.patch
build package set, reinstall overlay-scrollbar-gtk2_0.2.16+r359daily12.11.28.1-0ubuntu1 with the newly built .deb
log out/in
calibre should be fine
(note that the new, patched liboverlay-scrollbar.so will be slightly smaller, on my 64 bit install 73,112 bytes vs. 73,224 with the unpatched .so