I've done some hacking on the abook source. This is based off of the latest development version of abook at sourceforge (0.6.0pre2, with vCard import patch).
I made a git repo at repo.or.cz whose "master" branch tracks that base sourceforge version. The "profjim" branch tracks my changes. At this point, my changes are applied all in one chunk since I did the development on this a while back, before I started using git. But when I get the chance to go back to this, I'll break them up into smaller pieces and actually document what I've done.
For now, I'm afraid you're on your own. I recommend "git checkout profjim; git diff master".
I've also posted a PKGBUILD file for ArchLinux. I'm reluctant to put this into AUR until I've actually broken up and documented (and reviewed! it's been a while since I worked on this) my git branch. But it's here if you want to use it.
I've been using this version of abook myself since summer 2008 without issues.
See the PKGBUILD | git repository.