After upgrading to rpm-3.0.3-0.12, rpm -Uvh is causing severe problems for me. It appears to enter the new package version in the rpm database, and remove the old version, but the files from the new version are NEVER INSTALLED. So I am left with the package completely gone. This happened for me on both rawhide-release-19990814-1 and tar-1.13.6-1. Installing from scratch (also with rpm -Uvh) does not seem to be affected by this bug.
Fixed in rpm-3.0.3-13.