The Java.net maven 1 repository contains a placeholder for some of the OpenJPA 1.2.2 artifacts (ie openjpa-lib and openjpa-kernel). Unfortunately the maven release plugin detects the placeholder and downloads it as a jar and copies it into your local repository.
Having the jar in your local repository causes problems with the javadoc tool and the release plugin cannot continue.
Unfortunately this issue is not detected when doing a dryRun of the release:prepare goal - at least in my environment it only shows up when you start the release for real.
We use the Geronimo JPA spec jars elsewhere in the build - moving the TCK configuration to use them as well would resolve this issue.