Comment 33 for bug 578137

Sorry, it was not my intention to confuse you.
I meant exactly the same thing than Martin. In new-preinst (new being 2.3-1ubuntu3.2 in lucid and 2.3-1ubuntu6 in maverick) copy the content of /etc/gallery2 to a temp directory, let the old-postrm run, and then restore the files in the new-postinst.
I mentioned 2.3-1ubuntu2 because that's the version which introduced the problem and only upgrades from this version or newer will suffer from the bug.