I had rpm-4.0.3-0.55 installed on my machine. I "upgraded" to rpm-4.0.3-0.60. Simple queries like "rpm -q -i" and "rpm -q --scripts" stopped working. Furthermore, when I attempted to use "rpm -U --force" to reinstall the old rpm and rpm-build packages, it complained that only one major mode could be specified at a time. I finally had to (a) use rpm2cpio and cpio --extract to put back the files from the old version of rpm, (b) remove /etc/rpm/macros.db1, (c) restore my rpm database from a backup, and (d) rerun rpm -U on the packages I had installed along with rpm-4.0.3-0.60 to bring the database up-to-date. There is something wrong here.
Yes, the top level main() routine changed between -0.57 and -0.66 builds. You want rpm-4.0.3-0.66.