Comment 41 for bug 578137

Loïc, that's the proposed fix in comment #35. The latest upload to -proposed doesn't fix it because the files are unpacked before the postrm is executed. Hence the files from the new package are deleted. That's why I suggested to backup both /etc/gallery2 _and_ /usr/share/gallery2 in preinst.
This is not a really satisfying solution because we would mix files from the old package with the new one, but I don't see a better way to fix the package in lucid.